{"id":1082,"date":"2015-12-23T11:45:36","date_gmt":"2015-12-23T03:45:36","guid":{"rendered":"https:\/\/ai.zhousir.top\/?p=1082"},"modified":"2016-01-09T10:57:04","modified_gmt":"2016-01-09T02:57:04","slug":"android%e7%9a%84%e6%b6%88%e6%81%af%e5%a4%84%e7%90%86%e6%9c%ba%e5%88%b6","status":"publish","type":"post","link":"https:\/\/ai.zhousir.top\/?p=1082","title":{"rendered":"android\u7684\u6d88\u606f\u5904\u7406\u673a\u5236"},"content":{"rendered":"

android\u7684\u6d88\u606f\u5904\u7406\u6709\u4e09\u4e2a\u6838\u5fc3\u7c7b\uff1aLooper,Handler\u548cMessage\u3002\u5176\u5b9e\u8fd8\u6709\u4e00\u4e2aMessage Queue\uff08\u6d88\u606f\u961f\u5217\uff09\uff0c\u4f46\u662fMQ\u88ab\u5c01\u88c5\u5230Looper\u91cc\u9762\u4e86\uff0c\u6211\u4eec\u4e0d\u4f1a\u76f4\u63a5\u4e0eMQ\u6253\u4ea4\u9053\uff0c\u56e0\u6b64\u6211\u6ca1\u5c06\u5176\u4f5c\u4e3a\u6838\u5fc3\u7c7b\u3002\u4e0b\u9762\u4e00\u4e00\u4ecb\u7ecd\uff1a<\/p>\n

<\/p>\n

\u7ebf\u7a0b\u7684\u9b54\u6cd5\u5e08 Looper<\/span><\/strong><\/p>\n

Looper\u7684\u5b57\u9762\u610f\u601d\u662f\u201c\u5faa\u73af\u8005\u201d\uff0c\u5b83\u88ab\u8bbe\u8ba1\u7528\u6765\u4f7f\u4e00\u4e2a\u666e\u901a\u7ebf\u7a0b\u53d8\u6210Looper\u7ebf\u7a0b<\/b>\u3002\u6240\u8c13Looper\u7ebf\u7a0b\u5c31\u662f\u5faa\u73af\u5de5\u4f5c\u7684\u7ebf\u7a0b\u3002\u5728\u7a0b\u5e8f\u5f00\u53d1\u4e2d\uff08\u5c24\u5176\u662fGUI\u5f00\u53d1\u4e2d\uff09\uff0c\u6211\u4eec\u7ecf\u5e38\u4f1a\u9700\u8981\u4e00\u4e2a\u7ebf\u7a0b\u4e0d\u65ad\u5faa\u73af\uff0c\u4e00\u65e6\u6709\u65b0\u4efb\u52a1\u5219\u6267\u884c\uff0c\u6267\u884c\u5b8c\u7ee7\u7eed\u7b49\u5f85\u4e0b\u4e00\u4e2a\u4efb\u52a1\uff0c\u8fd9\u5c31\u662fLooper\u7ebf\u7a0b\u3002\u4f7f\u7528Looper\u7c7b\u521b\u5efaLooper\u7ebf\u7a0b\u5f88\u7b80\u5355\uff1a<\/p>\n

    \n
  1. public<\/b> class<\/b> LooperThread extends<\/b> Thread {\u00a0\u00a0<\/span><\/li>\n
  2. \u00a0\u00a0<\/span><\/li>\n
  3. @Override<\/span>\u00a0\u00a0<\/span><\/li>\n
  4. public<\/span><\/b> void<\/span><\/b> run() {\u00a0\u00a0<\/span><\/li>\n
  5. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5c06\u5f53\u524d\u7ebf\u7a0b\u521d\u59cb\u5316\u4e3aLooper\u7ebf\u7a0b <\/span>\u00a0\u00a0<\/span><\/li>\n
  6. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Looper.prepare();\u00a0\u00a0<\/span><\/li>\n
  7. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ …\u5176\u4ed6\u5904\u7406\uff0c\u5982\u5b9e\u4f8b\u5316handler <\/span>\u00a0\u00a0<\/span><\/li>\n
  8. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5f00\u59cb\u5faa\u73af\u5904\u7406\u6d88\u606f\u961f\u5217 <\/span>\u00a0\u00a0<\/span><\/li>\n
  9. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Looper.loop();\u00a0\u00a0<\/span><\/li>\n
  10. \u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
  11. } \u00a0<\/span><\/li>\n<\/ol>\n

    \u901a\u8fc7\u4e0a\u9762\u4e24\u884c\u6838\u5fc3\u4ee3\u7801\uff0c\u4f60\u7684\u7ebf\u7a0b\u5c31\u5347\u7ea7\u4e3aLooper\u7ebf\u7a0b\u4e86\uff01\uff01\uff01\u662f\u4e0d\u662f\u5f88\u795e\u5947\uff1f\u8ba9\u6211\u4eec\u653e\u6162\u955c\u5934\uff0c\u770b\u770b\u8fd9\u4e24\u884c\u4ee3\u7801\u5404\u81ea\u505a\u4e86\u4ec0\u4e48\u3002
    \n1)Looper.prepare()<\/span><\/p>\n

    \"\"<\/p>\n

    \u901a\u8fc7\u4e0a\u56fe\u53ef\u4ee5\u770b\u5230\uff0c\u73b0\u5728\u4f60\u7684\u7ebf\u7a0b\u4e2d\u6709\u4e00\u4e2aLooper\u5bf9\u8c61\uff0c\u5b83\u7684\u5185\u90e8\u7ef4\u62a4\u4e86\u4e00\u4e2a\u6d88\u606f\u961f\u5217MQ\u3002\u6ce8\u610f\uff0c\u4e00\u4e2aThread\u53ea\u80fd\u6709\u4e00\u4e2aLooper\u5bf9\u8c61<\/b>\uff0c\u4e3a\u4ec0\u4e48\u5462\uff1f\u54b1\u4eec\u6765\u770b\u6e90\u7801\u3002<\/p>\n

      \n
        \n
      1. public<\/b> class<\/b> Looper {\u00a0\u00a0<\/span><\/li>\n
      2. \u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u6bcf\u4e2a\u7ebf\u7a0b\u4e2d\u7684Looper\u5bf9\u8c61\u5176\u5b9e\u662f\u4e00\u4e2aThreadLocal\uff0c\u5373\u7ebf\u7a0b\u672c\u5730\u5b58\u50a8(TLS)\u5bf9\u8c61 <\/span>\u00a0\u00a0<\/span><\/li>\n
      3. \u00a0\u00a0\u00a0\u00a0<\/span>private<\/span><\/b> static<\/span><\/b> final<\/span><\/b> ThreadLocal sThreadLocal = <\/span>new<\/span><\/b> ThreadLocal();\u00a0\u00a0<\/span><\/li>\n
      4. \u00a0\u00a0<\/span><\/li>\n
      5. \u00a0\u00a0\u00a0\u00a0<\/span>\/\/ Looper\u5185\u7684\u6d88\u606f\u961f\u5217 <\/span>\u00a0\u00a0<\/span><\/li>\n
      6. \u00a0\u00a0\u00a0\u00a0<\/span>final<\/span><\/b> MessageQueue mQueue;\u00a0\u00a0<\/span><\/li>\n
      7. \u00a0\u00a0<\/span><\/li>\n
      8. \u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5f53\u524d\u7ebf\u7a0b <\/span>\u00a0\u00a0<\/span><\/li>\n
      9. \u00a0\u00a0\u00a0\u00a0Thread mThread;\u00a0\u00a0<\/span><\/li>\n
      10. \u00a0\u00a0<\/span><\/li>\n
      11. \u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u3002\u3002\u3002\u5176\u4ed6\u5c5e\u6027 <\/span>\u00a0\u00a0<\/span><\/li>\n
      12. \u00a0\u00a0<\/span><\/li>\n
      13. \u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u6bcf\u4e2aLooper\u5bf9\u8c61\u4e2d\u6709\u5b83\u7684\u6d88\u606f\u961f\u5217\uff0c\u548c\u5b83\u6240\u5c5e\u7684\u7ebf\u7a0b <\/span>\u00a0\u00a0<\/span><\/li>\n
      14. \u00a0\u00a0\u00a0\u00a0<\/span>private<\/span><\/b> Looper() {\u00a0\u00a0<\/span><\/li>\n
      15. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0mQueue = <\/span>new<\/span><\/b> MessageQueue();\u00a0\u00a0<\/span><\/li>\n
      16. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0mRun = <\/span>true<\/span><\/b>;\u00a0\u00a0<\/span><\/li>\n
      17. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0mThread = Thread.currentThread();\u00a0\u00a0<\/span><\/li>\n
      18. \u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
      19. \u00a0\u00a0<\/span><\/li>\n
      20. \u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u6211\u4eec\u8c03\u7528\u8be5\u65b9\u6cd5\u4f1a\u5728\u8c03\u7528\u7ebf\u7a0b\u7684TLS\u4e2d\u521b\u5efaLooper\u5bf9\u8c61 <\/span>\u00a0\u00a0<\/span><\/li>\n
      21. \u00a0\u00a0\u00a0\u00a0<\/span>public<\/span><\/b> static<\/span><\/b> final<\/span><\/b> void<\/span><\/b> prepare() {\u00a0\u00a0<\/span><\/li>\n
      22. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span><\/b> (sThreadLocal.get() != <\/span>null<\/span><\/b>) {\u00a0\u00a0<\/span><\/li>\n
      23. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u8bd5\u56fe\u5728\u6709Looper\u7684\u7ebf\u7a0b\u4e2d\u518d\u6b21\u521b\u5efaLooper\u5c06\u629b\u51fa\u5f02\u5e38 <\/span>\u00a0\u00a0<\/span><\/li>\n
      24. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>throw<\/span><\/b> new<\/span><\/b> RuntimeException(<\/span>“Only one Looper may be created per thread”<\/span>);\u00a0\u00a0<\/span><\/li>\n
      25. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
      26. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0sThreadLocal.set(<\/span>new<\/span><\/b> Looper());\u00a0\u00a0<\/span><\/li>\n
      27. \u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
      28. \u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5176\u4ed6\u65b9\u6cd5 <\/span>\u00a0\u00a0<\/span><\/li>\n
      29. }<\/span><\/li>\n
      30. <\/li>\n<\/ol>\n<\/ol>\n

        \u901a\u8fc7\u6e90\u7801\uff0cprepare()\u80cc\u540e\u7684\u5de5\u4f5c\u65b9\u5f0f\u4e00\u76ee\u4e86\u7136\uff0c\u5176\u6838\u5fc3\u5c31\u662f\u5c06looper\u5bf9\u8c61\u5b9a\u4e49\u4e3aThreadLocal\u3002\u5982\u679c\u4f60\u8fd8\u4e0d\u6e05\u695a\u4ec0\u4e48\u662fThreadLocal\uff0c\u8bf7\u53c2\u8003\u300a\u7406\u89e3ThreadLocal\u300b<\/a>\u3002
        \n2\uff09Looper.loop()<\/span><\/p>\n

        \"\"<\/p>\n

        \u8c03\u7528loop\u65b9\u6cd5\u540e\uff0cLooper\u7ebf\u7a0b\u5c31\u5f00\u59cb\u771f\u6b63\u5de5\u4f5c\u4e86\uff0c\u5b83\u4e0d\u65ad\u4ece\u81ea\u5df1\u7684MQ\u4e2d\u53d6\u51fa\u961f\u5934\u7684\u6d88\u606f(\u4e5f\u53eb\u4efb\u52a1)\u6267\u884c\u3002\u5176\u6e90\u7801\u5206\u6790\u5982\u4e0b\uff1a<\/p>\n

          \n
        1. public<\/b> static<\/b> final<\/b> void<\/b> loop() {\u00a0\u00a0<\/span><\/li>\n
        2. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Looper me = myLooper();\u00a0\u00a0<\/span>\/\/\u5f97\u5230\u5f53\u524d\u7ebf\u7a0bLooper <\/span>\u00a0\u00a0<\/span><\/li>\n
        3. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0MessageQueue queue = me.mQueue;\u00a0\u00a0<\/span>\/\/\u5f97\u5230\u5f53\u524dlooper\u7684MQ <\/span>\u00a0\u00a0<\/span><\/li>\n
        4. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u8fd9\u4e24\u884c\u6ca1\u770b\u61c2= = \u4e0d\u8fc7\u4e0d\u5f71\u54cd\u7406\u89e3 <\/span>\u00a0\u00a0<\/span><\/li>\n
        5. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Binder.clearCallingIdentity();\u00a0\u00a0<\/span><\/li>\n
        6. \u00a0\u00a0<\/span><\/li>\n
        7. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>final<\/span><\/b> long<\/span><\/b> ident = Binder.clearCallingIdentity();\u00a0\u00a0<\/span><\/li>\n
        8. \u00a0\u00a0<\/span><\/li>\n
        9. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5f00\u59cb\u5faa\u73af <\/span>\u00a0\u00a0<\/span><\/li>\n
        10. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>while<\/span><\/b> (<\/span>true<\/span><\/b>) {\u00a0\u00a0<\/span><\/li>\n
        11. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Message msg = queue.next(); <\/span>\/\/ \u53d6\u51famessage <\/span>\u00a0\u00a0<\/span><\/li>\n
        12. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span><\/b> (msg != <\/span>null<\/span><\/b>) {\u00a0\u00a0<\/span><\/li>\n
        13. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span><\/b> (msg.target == <\/span>null<\/span><\/b>) {\u00a0\u00a0<\/span><\/li>\n
        14. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ message\u6ca1\u6709target\u4e3a\u7ed3\u675f\u4fe1\u53f7\uff0c\u9000\u51fa\u5faa\u73af <\/span>\u00a0\u00a0<\/span><\/li>\n
        15. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>return<\/span><\/b>;\u00a0\u00a0<\/span><\/li>\n
        16. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
        17. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u65e5\u5fd7\u3002\u3002\u3002 <\/span>\u00a0\u00a0<\/span><\/li>\n
        18. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span><\/b> (me.mLogging!= <\/span>null<\/span><\/b>) me.mLogging.println(\u00a0\u00a0<\/span><\/li>\n
        19. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>“>>>>> Dispatching to “<\/span> + msg.target + <\/span>” “<\/span>\u00a0\u00a0<\/span><\/li>\n
        20. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0+ msg.callback + <\/span>“: “<\/span> + msg.what\u00a0\u00a0<\/span><\/li>\n
        21. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0);\u00a0\u00a0<\/span><\/li>\n
        22. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u975e\u5e38\u91cd\u8981\uff01\u5c06\u771f\u6b63\u7684\u5904\u7406\u5de5\u4f5c\u4ea4\u7ed9message\u7684target\uff0c\u5373\u540e\u9762\u8981\u8bb2\u7684handler <\/span>\u00a0\u00a0<\/span><\/li>\n
        23. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0msg.target.dispatchMessage(msg);\u00a0\u00a0<\/span><\/li>\n
        24. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u8fd8\u662f\u65e5\u5fd7\u3002\u3002\u3002 <\/span>\u00a0\u00a0<\/span><\/li>\n
        25. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span><\/b> (me.mLogging!= <\/span>null<\/span><\/b>) me.mLogging.println(\u00a0\u00a0<\/span><\/li>\n
        26. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>“<<<<< Finished to\u00a0\u00a0\u00a0\u00a0“<\/span> + msg.target + <\/span>” “<\/span>\u00a0\u00a0<\/span><\/li>\n
        27. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0+ msg.callback);\u00a0\u00a0<\/span><\/li>\n
        28. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u4e0b\u9762\u6ca1\u770b\u61c2\uff0c\u540c\u6837\u4e0d\u5f71\u54cd\u7406\u89e3 <\/span>\u00a0\u00a0<\/span><\/li>\n
        29. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>final<\/span><\/b> long<\/span><\/b> newIdent = Binder.clearCallingIdentity();\u00a0\u00a0<\/span><\/li>\n
        30. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span><\/b> (ident != newIdent) {\u00a0\u00a0<\/span><\/li>\n
        31. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Log.wtf(<\/span>“Looper”<\/span>, <\/span>“Thread identity changed from 0x”<\/span>\u00a0\u00a0<\/span><\/li>\n
        32. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0+ Long.toHexString(ident) + <\/span>” to 0x”<\/span>\u00a0\u00a0<\/span><\/li>\n
        33. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0+ Long.toHexString(newIdent) + <\/span>” while dispatching to “<\/span>\u00a0\u00a0<\/span><\/li>\n
        34. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0+ msg.target.getClass().getName() + <\/span>” “<\/span>+ msg.callback + <\/span>” what=”<\/span> + msg.what);\u00a0\u00a0<\/span><\/li>\n
        35. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
        36. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u56de\u6536message\u8d44\u6e90 <\/span>\u00a0\u00a0<\/span><\/li>\n
        37. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0msg.recycle();\u00a0\u00a0<\/span><\/li>\n
        38. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
        39. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
        40. \u00a0\u00a0\u00a0\u00a0}\u00a0<\/span><\/li>\n<\/ol>\n

          \u9664\u4e86prepare()\u548cloop()\u65b9\u6cd5\uff0cLooper\u7c7b\u8fd8\u63d0\u4f9b\u4e86\u4e00\u4e9b\u6709\u7528\u7684\u65b9\u6cd5\uff0c\u6bd4\u5982
          \nLooper.myLooper()\u5f97\u5230\u5f53\u524d\u7ebf\u7a0blooper\u5bf9\u8c61\uff1a<\/p>\n

            \n
          1. public<\/b> static<\/b> final<\/b> Looper myLooper() {\u00a0\u00a0<\/span><\/li>\n
          2. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5728\u4efb\u610f\u7ebf\u7a0b\u8c03\u7528Looper.myLooper()\u8fd4\u56de\u7684\u90fd\u662f\u90a3\u4e2a\u7ebf\u7a0b\u7684looper <\/span>\u00a0\u00a0<\/span><\/li>\n
          3. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>return<\/span><\/b> (Looper)sThreadLocal.get();\u00a0\u00a0<\/span><\/li>\n
          4. }\u00a0\u00a0<\/span><\/li>\n<\/ol>\n

            getThread()\u5f97\u5230looper\u5bf9\u8c61\u6240\u5c5e\u7ebf\u7a0b\uff1a<\/p>\n

              \n
            1. public<\/b> Thread getThread() {\u00a0\u00a0<\/span><\/li>\n
            2. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>return<\/span><\/b> mThread;\u00a0\u00a0<\/span><\/li>\n
            3. }\u00a0\u00a0<\/span><\/li>\n<\/ol>\n

              quit()\u65b9\u6cd5\u7ed3\u675flooper\u5faa\u73af\uff1a<\/p>\n

              \u9664\u4e86prepare()\u548cloop()\u65b9\u6cd5\uff0cLooper\u7c7b\u8fd8\u63d0\u4f9b\u4e86\u4e00\u4e9b\u6709\u7528\u7684\u65b9\u6cd5\uff0c\u6bd4\u5982
              \nLooper.myLooper()\u5f97\u5230\u5f53\u524d\u7ebf\u7a0blooper\u5bf9\u8c61\uff1a<\/p>\n

                \n
              1. public<\/b> static<\/b> final<\/b> Looper myLooper() {\u00a0\u00a0<\/span><\/li>\n
              2. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5728\u4efb\u610f\u7ebf\u7a0b\u8c03\u7528Looper.myLooper()\u8fd4\u56de\u7684\u90fd\u662f\u90a3\u4e2a\u7ebf\u7a0b\u7684looper <\/span>\u00a0\u00a0<\/span><\/li>\n
              3. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>return<\/span><\/b> (Looper)sThreadLocal.get();\u00a0\u00a0<\/span><\/li>\n
              4. }\u00a0\u00a0<\/span><\/li>\n<\/ol>\n

                getThread()\u5f97\u5230looper\u5bf9\u8c61\u6240\u5c5e\u7ebf\u7a0b\uff1a<\/p>\n

                  \n
                1. public<\/b> Thread getThread() {\u00a0\u00a0<\/span><\/li>\n
                2. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>return<\/span><\/b> mThread;\u00a0\u00a0<\/span><\/li>\n
                3. }\u00a0\u00a0<\/span><\/li>\n<\/ol>\n

                  quit()\u65b9\u6cd5\u7ed3\u675flooper\u5faa\u73af\uff1a<\/p>\n

                    \n
                  1. public<\/b> void<\/b> quit() {\u00a0\u00a0<\/span><\/li>\n
                  2. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u521b\u5efa\u4e00\u4e2a\u7a7a\u7684message\uff0c\u5b83\u7684target\u4e3aNULL\uff0c\u8868\u793a\u7ed3\u675f\u5faa\u73af\u6d88\u606f <\/span>\u00a0\u00a0<\/span><\/li>\n
                  3. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Message msg = Message.obtain();\u00a0\u00a0<\/span><\/li>\n
                  4. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u53d1\u51fa\u6d88\u606f <\/span>\u00a0\u00a0<\/span><\/li>\n
                  5. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0mQueue.enqueueMessage(msg, <\/span>0<\/span>);\u00a0\u00a0<\/span><\/li>\n
                  6. }\u00a0\u00a0<\/span><\/li>\n<\/ol>\n

                    \u5230\u6b64\u4e3a\u6b62\uff0c\u4f60\u5e94\u8be5\u5bf9Looper\u6709\u4e86\u57fa\u672c\u7684\u4e86\u89e3\uff0c\u603b\u7ed3\u51e0\u70b9\uff1a
                    \n1.\u6bcf\u4e2a\u7ebf\u7a0b\u6709\u4e14\u6700\u591a\u53ea\u80fd\u6709\u4e00\u4e2aLooper\u5bf9\u8c61\uff0c\u5b83\u662f\u4e00\u4e2aThreadLocal
                    \n2.Looper\u5185\u90e8\u6709\u4e00\u4e2a\u6d88\u606f\u961f\u5217\uff0cloop()\u65b9\u6cd5\u8c03\u7528\u540e\u7ebf\u7a0b\u5f00\u59cb\u4e0d\u65ad\u4ece\u961f\u5217\u4e2d\u53d6\u51fa\u6d88\u606f\u6267\u884c
                    \n3.Looper\u4f7f\u4e00\u4e2a\u7ebf\u7a0b\u53d8\u6210Looper\u7ebf\u7a0b\u3002
                    \n\u90a3\u4e48\uff0c\u6211\u4eec\u5982\u4f55\u5f80MQ\u4e0a\u6dfb\u52a0\u6d88\u606f\u5462\uff1f\u4e0b\u9762\u6709\u8bf7Handler\uff01<\/p>\n

                    \u5f02\u6b65\u5904\u7406\u5927\u5e08 Handler<\/b><\/p>\n

                    \u4ec0\u4e48\u662fhandler\uff1fhandler\u626e\u6f14\u4e86\u5f80MQ\u4e0a\u6dfb\u52a0\u6d88\u606f\u548c\u5904\u7406\u6d88\u606f\u7684\u89d2\u8272\uff08\u53ea\u5904\u7406\u7531\u81ea\u5df1\u53d1\u51fa\u7684\u6d88\u606f\uff09\uff0c\u5373<\/span>\u901a\u77e5MQ\u5b83\u8981\u6267\u884c\u4e00\u4e2a\u4efb\u52a1(sendMessage)\uff0c\u5e76\u5728loop\u5230\u81ea\u5df1\u7684\u65f6\u5019\u6267\u884c\u8be5\u4efb\u52a1(handleMessage)\uff0c\u6574\u4e2a\u8fc7\u7a0b\u662f\u5f02\u6b65\u7684<\/b>\u3002handler\u521b\u5efa\u65f6\u4f1a\u5173\u8054\u4e00\u4e2alooper\uff0c\u9ed8\u8ba4\u7684\u6784\u9020\u65b9\u6cd5\u5c06\u5173\u8054\u5f53\u524d\u7ebf\u7a0b\u7684looper\uff0c\u4e0d\u8fc7\u8fd9\u4e5f\u662f\u53ef\u4ee5set\u7684\u3002\u9ed8\u8ba4\u7684\u6784\u9020\u65b9\u6cd5\uff1a<\/span><\/p>\n

                      \n
                        \n
                      1. public<\/b> class<\/b> handler {\u00a0\u00a0<\/span><\/li>\n
                      2. \u00a0\u00a0\u00a0\u00a0<\/span>final<\/span><\/b> MessageQueue mQueue;\u00a0\u00a0<\/span>\/\/ \u5173\u8054\u7684MQ <\/span>\u00a0\u00a0<\/span><\/li>\n
                      3. \u00a0\u00a0<\/span><\/li>\n
                      4. \u00a0\u00a0\u00a0\u00a0<\/span>final<\/span><\/b> Looper mLooper;\u00a0\u00a0<\/span>\/\/ \u5173\u8054\u7684looper <\/span>\u00a0\u00a0<\/span><\/li>\n
                      5. \u00a0\u00a0<\/span><\/li>\n
                      6. \u00a0\u00a0\u00a0\u00a0<\/span>final<\/span><\/b> Callback mCallback;\u00a0\u00a0<\/span><\/li>\n
                      7. \u00a0\u00a0<\/span><\/li>\n
                      8. \u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5176\u4ed6\u5c5e\u6027 <\/span>\u00a0\u00a0<\/span><\/li>\n
                      9. \u00a0\u00a0<\/span><\/li>\n
                      10. \u00a0\u00a0\u00a0\u00a0<\/span>public<\/span><\/b> Handler() {\u00a0\u00a0<\/span><\/li>\n
                      11. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u6ca1\u770b\u61c2\uff0c\u76f4\u63a5\u7565\u8fc7\uff0c\uff0c\uff0c <\/span>\u00a0\u00a0<\/span><\/li>\n
                      12. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span><\/b> (FIND_POTENTIAL_LEAKS) {\u00a0\u00a0<\/span><\/li>\n
                      13. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>final<\/span><\/b> Class<? <\/span>extends<\/span><\/b> Handler> klass = getClass();\u00a0\u00a0<\/span><\/li>\n
                      14. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span><\/b> ((klass.isAnonymousClass() || klass.isMemberClass() || klass.isLocalClass()) &&\u00a0\u00a0<\/span><\/li>\n
                      15. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0(klass.getModifiers() & Modifier.STATIC) == <\/span>0<\/span>) {\u00a0\u00a0<\/span><\/li>\n
                      16. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Log.w(TAG, <\/span>“The following Handler class should be static or leaks might occur: “<\/span> +\u00a0\u00a0<\/span><\/li>\n
                      17. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0klass.getCanonicalName());\u00a0\u00a0<\/span><\/li>\n
                      18. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
                      19. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
                      20. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u9ed8\u8ba4\u5c06\u5173\u8054\u5f53\u524d\u7ebf\u7a0b\u7684looper <\/span>\u00a0\u00a0<\/span><\/li>\n
                      21. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0mLooper = Looper.myLooper();\u00a0\u00a0<\/span><\/li>\n
                      22. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ looper\u4e0d\u80fd\u4e3a\u7a7a\uff0c\u5373\u8be5\u9ed8\u8ba4\u7684\u6784\u9020\u65b9\u6cd5\u53ea\u80fd\u5728looper\u7ebf\u7a0b\u4e2d\u4f7f\u7528 <\/span>\u00a0\u00a0<\/span><\/li>\n
                      23. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span><\/b> (mLooper == <\/span>null<\/span><\/b>) {\u00a0\u00a0<\/span><\/li>\n
                      24. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>throw<\/span><\/b> new<\/span><\/b> RuntimeException(\u00a0\u00a0<\/span><\/li>\n
                      25. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>“Can’t create handler inside thread that has not called Looper.prepare()”<\/span>);\u00a0\u00a0<\/span><\/li>\n
                      26. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
                      27. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u91cd\u8981\uff01\uff01\uff01\u76f4\u63a5\u628a\u5173\u8054looper\u7684MQ\u4f5c\u4e3a\u81ea\u5df1\u7684MQ\uff0c\u56e0\u6b64\u5b83\u7684\u6d88\u606f\u5c06\u53d1\u9001\u5230\u5173\u8054looper\u7684MQ\u4e0a <\/span>\u00a0\u00a0<\/span><\/li>\n
                      28. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0mQueue = mLooper.mQueue;\u00a0\u00a0<\/span><\/li>\n
                      29. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0mCallback = <\/span>null<\/span><\/b>;\u00a0\u00a0<\/span><\/li>\n
                      30. \u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
                      31. \u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5176\u4ed6\u65b9\u6cd5 <\/span>\u00a0\u00a0<\/span><\/li>\n
                      32. }<\/span><\/li>\n<\/ol>\n<\/ol>\n

                        \u4e0b\u9762\u6211\u4eec\u5c31\u53ef\u4ee5\u4e3a\u4e4b\u524d\u7684LooperThread\u7c7b\u52a0\u5165Handler\uff1a<\/p>\n

                          \n
                            \n
                          1. <\/li>\n
                          2. public<\/b> class<\/b> LooperThread extends<\/b> Thread {\u00a0\u00a0<\/span><\/li>\n
                          3. \u00a0\u00a0\u00a0\u00a0<\/span>private<\/span><\/b> Handler handler1;\u00a0\u00a0<\/span><\/li>\n
                          4. \u00a0\u00a0<\/span><\/li>\n
                          5. \u00a0\u00a0\u00a0\u00a0<\/span>private<\/span><\/b> Handler handler2;\u00a0\u00a0<\/span><\/li>\n
                          6. \u00a0\u00a0<\/span><\/li>\n
                          7. \u00a0\u00a0\u00a0\u00a0<\/span>@Override<\/span>\u00a0\u00a0<\/span><\/li>\n
                          8. \u00a0\u00a0\u00a0\u00a0<\/span>public<\/span><\/b> void<\/span><\/b> run() {\u00a0\u00a0<\/span><\/li>\n
                          9. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5c06\u5f53\u524d\u7ebf\u7a0b\u521d\u59cb\u5316\u4e3aLooper\u7ebf\u7a0b <\/span>\u00a0\u00a0<\/span><\/li>\n
                          10. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Looper.prepare();\u00a0\u00a0<\/span><\/li>\n
                          11. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5b9e\u4f8b\u5316\u4e24\u4e2ahandler <\/span>\u00a0\u00a0<\/span><\/li>\n
                          12. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0handler1 = <\/span>new<\/span><\/b> Handler();\u00a0\u00a0<\/span><\/li>\n
                          13. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0handler2 = <\/span>new<\/span><\/b> Handler();\u00a0\u00a0<\/span><\/li>\n
                          14. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5f00\u59cb\u5faa\u73af\u5904\u7406\u6d88\u606f\u961f\u5217 <\/span>\u00a0\u00a0<\/span><\/li>\n
                          15. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Looper.loop();\u00a0\u00a0<\/span><\/li>\n
                          16. \u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
                          17. }<\/span><\/li>\n<\/ol>\n<\/ol>\n

                            \u52a0\u5165handler\u540e\u7684\u6548\u679c\u5982\u4e0b\u56fe\uff1a<\/p>\n

                            \"\"<\/p>\n

                            \u53ef\u4ee5\u770b\u5230\uff0c<\/span>\u4e00\u4e2a\u7ebf\u7a0b\u53ef\u4ee5\u6709\u591a\u4e2aHandler\uff0c\u4f46\u662f\u53ea\u80fd\u6709\u4e00\u4e2aLooper\uff01<\/b>
                            \nHandler\u53d1\u9001\u6d88\u606f
                            \n<\/b><\/span>
                            \n\u6709\u4e86handler\u4e4b\u540e\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u4f7f\u7528 <\/span>post(Runnable)<\/a>,<\/span>postAtTime(Runnable, long)<\/a>,<\/span>postDelayed(Runnable, long)<\/a>,<\/span>sendEmptyMessage(int)<\/a>,<\/span>sendMessage(Message)<\/a>,<\/span>sendMessageAtTime(Message, long)<\/a>\u548c<\/span>sendMessageDelayed(Message, long)<\/a>\u8fd9\u4e9b\u65b9\u6cd5\u5411MQ\u4e0a\u53d1\u9001\u6d88\u606f\u4e86\u3002\u5149\u770b\u8fd9\u4e9bAPI\u4f60\u53ef\u80fd\u4f1a\u89c9\u5f97handler\u80fd\u53d1\u4e24\u79cd\u6d88\u606f\uff0c\u4e00\u79cd\u662fRunnable\u5bf9\u8c61\uff0c\u4e00\u79cd\u662fmessage\u5bf9\u8c61\uff0c\u8fd9\u662f\u76f4\u89c2\u7684\u7406\u89e3\uff0c\u4f46\u5176\u5b9epost\u53d1\u51fa\u7684Runnable\u5bf9\u8c61\u6700\u540e\u90fd\u88ab\u5c01\u88c5\u6210message\u5bf9\u8c61\u4e86\uff0c\u89c1\u6e90\u7801\uff1a<\/span><\/p>\n

                              \n
                            1. public<\/b> final<\/b> boolean<\/b> post(Runnable r)\u00a0\u00a0<\/span><\/li>\n
                            2. {\u00a0\u00a0<\/span><\/li>\n
                            3. \u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u6ce8\u610fgetPostMessage(r)\u5c06runnable\u5c01\u88c5\u6210message <\/span>\u00a0\u00a0<\/span><\/li>\n
                            4. \u00a0\u00a0\u00a0\u00a0<\/span>return<\/span><\/b>\u00a0\u00a0sendMessageDelayed(getPostMessage(r), <\/span>0<\/span>);\u00a0\u00a0<\/span><\/li>\n
                            5. }\u00a0\u00a0<\/span><\/li>\n
                            6. \u00a0\u00a0<\/span><\/li>\n
                            7. private<\/span><\/b> final<\/span><\/b> Message getPostMessage(Runnable r) {\u00a0\u00a0<\/span><\/li>\n
                            8. \u00a0\u00a0<\/span><\/li>\n
                            9. \u00a0\u00a0\u00a0\u00a0 Message m = Message.obtain();\u00a0\u00a0<\/span>\/\/\u5f97\u5230\u7a7a\u7684message <\/span>\u00a0\u00a0<\/span><\/li>\n
                            10. \u00a0\u00a0\u00a0\u00a0 m.callback = r;\u00a0\u00a0<\/span>\/\/\u5c06runnable\u8bbe\u4e3amessage\u7684callback <\/span>\u00a0\u00a0<\/span><\/li>\n
                            11. \u00a0\u00a0\u00a0\u00a0 <\/span>return<\/span><\/b> m;\u00a0\u00a0<\/span><\/li>\n
                            12. }\u00a0\u00a0<\/span><\/li>\n
                            13. \u00a0\u00a0<\/span><\/li>\n
                            14. public<\/span><\/b> boolean<\/span><\/b> sendMessageAtTime(Message msg, <\/span>long<\/span><\/b> uptimeMillis)\u00a0\u00a0<\/span><\/li>\n
                            15. {\u00a0\u00a0<\/span><\/li>\n
                            16. \u00a0\u00a0\u00a0\u00a0 <\/span>boolean<\/span><\/b> sent = <\/span>false<\/span><\/b>;\u00a0\u00a0<\/span><\/li>\n
                            17. \u00a0\u00a0\u00a0\u00a0 MessageQueue queue = mQueue;\u00a0\u00a0<\/span><\/li>\n
                            18. \u00a0\u00a0\u00a0\u00a0 <\/span>if<\/span><\/b> (queue != <\/span>null<\/span><\/b>) {\u00a0\u00a0<\/span><\/li>\n
                            19. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 msg.target = <\/span>this<\/span><\/b>;\u00a0\u00a0<\/span>\/\/ message\u7684target\u5fc5\u987b\u8bbe\u4e3a\u8be5handler\uff01 <\/span>\u00a0\u00a0<\/span><\/li>\n
                            20. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 sent = queue.enqueueMessage(msg, uptimeMillis);\u00a0\u00a0<\/span><\/li>\n
                            21. \u00a0\u00a0\u00a0\u00a0 }\u00a0\u00a0<\/span><\/li>\n
                            22. \u00a0\u00a0\u00a0\u00a0 <\/span>else<\/span><\/b> {\u00a0\u00a0<\/span><\/li>\n
                            23. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 RuntimeException e = <\/span>new<\/span><\/b> RuntimeException(\u00a0\u00a0<\/span><\/li>\n
                            24. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span>this<\/span><\/b> + <\/span>” sendMessageAtTime() called with no mQueue”<\/span>);\u00a0\u00a0<\/span><\/li>\n
                            25. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Log.w(<\/span>“Looper”<\/span>, e.getMessage(), e);\u00a0\u00a0<\/span><\/li>\n
                            26. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
                            27. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>return<\/span><\/b> sent;\u00a0\u00a0<\/span><\/li>\n
                            28. }<\/span><\/li>\n<\/ol>\n

                              \u5176\u4ed6\u65b9\u6cd5\u5c31\u4e0d\u7f57\u5217\u4e86\uff0c\u603b\u4e4b\u901a\u8fc7handler\u53d1\u51fa\u7684message\u6709\u5982\u4e0b\u7279\u70b9\uff1a<\/span>
                              \n1.message.target\u4e3a\u8be5handler\u5bf9\u8c61\uff0c\u8fd9\u786e\u4fdd\u4e86looper\u6267\u884c\u5230\u8be5message\u65f6\u80fd\u627e\u5230\u5904\u7406\u5b83\u7684handler\uff0c\u5373loop()\u65b9\u6cd5\u4e2d\u7684\u5173\u952e\u4ee3\u7801<\/span>
                              \nmsg.target.dispatchMessage(msg);<\/span>
                              \n2.post\u53d1\u51fa\u7684message\uff0c\u5176callback\u4e3aRunnable\u5bf9\u8c61<\/span>
                              \nHandler\u5904\u7406\u6d88\u606f<\/b><\/span>
                              \n\u8bf4\u5b8c\u4e86\u6d88\u606f\u7684\u53d1\u9001\uff0c\u518d\u6765\u770b\u4e0bhandler\u5982\u4f55\u5904\u7406\u6d88\u606f\u3002\u6d88\u606f\u7684\u5904\u7406\u662f\u901a\u8fc7\u6838\u5fc3\u65b9\u6cd5<\/span>                              dispatchMessage<\/a>(<\/span>Message<\/a> msg)\u4e0e\u94a9\u5b50\u65b9\u6cd5<\/span>handleMessage<\/a>(<\/span>Message<\/a>\u00a0msg)\u5b8c\u6210\u7684\uff0c\u89c1\u6e90\u7801<\/span><\/p>\n

                                \n
                              1. \/\/ \u5904\u7406\u6d88\u606f\uff0c\u8be5\u65b9\u6cd5\u7531looper\u8c03\u7528 \u00a0\u00a0<\/span><\/li>\n
                              2. public<\/span><\/b> void<\/span><\/b> dispatchMessage(Message msg) {\u00a0\u00a0<\/span><\/li>\n
                              3. \u00a0\u00a0\u00a0\u00a0<\/span>if<\/span><\/b> (msg.callback != <\/span>null<\/span><\/b>) {\u00a0\u00a0<\/span><\/li>\n
                              4. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5982\u679cmessage\u8bbe\u7f6e\u4e86callback\uff0c\u5373runnable\u6d88\u606f\uff0c\u5904\u7406callback\uff01 <\/span>\u00a0\u00a0<\/span><\/li>\n
                              5. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0handleCallback(msg);\u00a0\u00a0<\/span><\/li>\n
                              6. \u00a0\u00a0\u00a0\u00a0} <\/span>else<\/span><\/b> {\u00a0\u00a0<\/span><\/li>\n
                              7. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5982\u679chandler\u672c\u8eab\u8bbe\u7f6e\u4e86callback\uff0c\u5219\u6267\u884ccallback <\/span>\u00a0\u00a0<\/span><\/li>\n
                              8. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span><\/b> (mCallback != <\/span>null<\/span><\/b>) {\u00a0\u00a0<\/span><\/li>\n
                              9. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span>\/* \u8fd9\u79cd\u65b9\u6cd5\u5141\u8bb8\u8ba9activity\u7b49\u6765\u5b9e\u73b0Handler.Callback\u63a5\u53e3\uff0c\u907f\u514d\u4e86\u81ea\u5df1\u7f16\u5199handler\u91cd\u5199handleMessage\u65b9\u6cd5\u3002\u89c1http:\/\/alex-yang-xiansoftware-com.iteye.com\/blog\/850865 *\/<\/span>\u00a0\u00a0<\/span><\/li>\n
                              10. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span><\/b> (mCallback.handleMessage(msg)) {\u00a0\u00a0<\/span><\/li>\n
                              11. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>return<\/span><\/b>;\u00a0\u00a0<\/span><\/li>\n
                              12. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
                              13. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
                              14. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5982\u679cmessage\u6ca1\u6709callback\uff0c\u5219\u8c03\u7528handler\u7684\u94a9\u5b50\u65b9\u6cd5handleMessage <\/span>\u00a0\u00a0<\/span><\/li>\n
                              15. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0handleMessage(msg);\u00a0\u00a0<\/span><\/li>\n
                              16. \u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0<\/span><\/li>\n
                              17. }\u00a0\u00a0<\/span><\/li>\n
                              18. \u00a0\u00a0<\/span><\/li>\n
                              19. \u00a0\u00a0\u00a0\u00a0<\/span>\/\/ \u5904\u7406runnable\u6d88\u606f <\/span>\u00a0\u00a0<\/span><\/li>\n
                              20. private<\/span><\/b> final<\/span><\/b> void<\/span><\/b> handleCallback(Message message) {\u00a0\u00a0<\/span><\/li>\n
                              21. \u00a0\u00a0\u00a0\u00a0message.callback.run();\u00a0\u00a0<\/span>\/\/\u76f4\u63a5\u8c03\u7528run\u65b9\u6cd5\uff01 <\/span>\u00a0\u00a0<\/span><\/li>\n
                              22. }\u00a0\u00a0<\/span><\/li>\n
                              23. \u00a0\u00a0<\/span><\/li>\n
                              24. \/\/ \u7531\u5b50\u7c7b\u5b9e\u73b0\u7684\u94a9\u5b50\u65b9\u6cd5 <\/span>\u00a0\u00a0<\/span><\/li>\n
                              25. public<\/span><\/b> void<\/span><\/b> handleMessage(Message msg) {\u00a0\u00a0<\/span><\/li>\n
                              26. }\u00a0\u00a0<\/span><\/li>\n<\/ol>\n

                                \u53ef\u4ee5\u770b\u5230\uff0c\u9664\u4e86<\/span>handleMessage<\/a>(<\/span>Message<\/a> msg)\u548cRunnable\u5bf9\u8c61\u7684run\u65b9\u6cd5\u7531\u5f00\u53d1\u8005\u5b9e\u73b0\u5916\uff08\u5b9e\u73b0\u5177\u4f53\u903b\u8f91\uff09\uff0chandler\u7684\u5185\u90e8\u5de5\u4f5c\u673a\u5236\u5bf9\u5f00\u53d1\u8005\u662f\u900f\u660e\u7684\u3002\u8fd9\u6b63\u662fhandler API\u8bbe\u8ba1\u7684\u7cbe\u5999\u4e4b\u5904\uff01<\/span>
                                \nHandler\u7684\u7528\u5904<\/b><\/span>
                                \n\u6211\u5728\u5c0f\u6807\u9898\u4e2d\u5c06handler\u63cf\u8ff0\u4e3a\u201c\u5f02\u6b65\u5904\u7406\u5927\u5e08\u201d\uff0c\u8fd9\u5f52\u529f\u4e8eHandler\u62e5\u6709\u4e0b\u9762\u4e24\u4e2a\u91cd\u8981\u7684\u7279\u70b9\uff1a<\/span>
                                \n1.handler\u53ef\u4ee5\u5728<\/span>\u4efb\u610f\u7ebf\u7a0b\u53d1\u9001\u6d88\u606f<\/b>\uff0c\u8fd9\u4e9b\u6d88\u606f\u4f1a\u88ab\u6dfb\u52a0\u5230\u5173\u8054\u7684MQ\u4e0a\u3002<\/span>
                                \n\"\"\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>
                                \n2.handler\u662f\u5728\u5b83<\/span>\u5173\u8054\u7684looper\u7ebf\u7a0b\u4e2d\u5904\u7406\u6d88\u606f<\/b>\u7684\u3002<\/span>
                                \n\"\"
                                \n\u8fd9\u5c31\u89e3\u51b3\u4e86android\u6700\u7ecf\u5178\u7684\u4e0d\u80fd\u5728\u5176\u4ed6\u975e\u4e3b\u7ebf\u7a0b\u4e2d\u66f4\u65b0UI\u7684\u95ee\u9898\u3002<\/span>android\u7684\u4e3b\u7ebf\u7a0b\u4e5f\u662f\u4e00\u4e2alooper\u7ebf\u7a0b<\/b>(looper\u5728android\u4e2d\u8fd0\u7528\u5f88\u5e7f)\uff0c\u6211\u4eec\u5728\u5176\u4e2d\u521b\u5efa\u7684handler\u9ed8\u8ba4\u5c06\u5173\u8054\u4e3b\u7ebf\u7a0bMQ\u3002\u56e0\u6b64\uff0c\u5229\u7528handler\u7684\u4e00\u4e2asolution\u5c31\u662f\u5728activity\u4e2d\u521b\u5efahandler\u5e76\u5c06\u5176\u5f15\u7528\u4f20\u9012\u7ed9worker thread\uff0cworker thread\u6267\u884c\u5b8c\u4efb\u52a1\u540e\u4f7f\u7528handler\u53d1\u9001\u6d88\u606f\u901a\u77e5activity\u66f4\u65b0UI\u3002(\u8fc7\u7a0b\u5982\u56fe)<\/span>
                                \n\"\"
                                \n\u5f53\u7136\uff0chandler\u80fd\u505a\u7684\u8fdc\u8fdc\u4e0d\u4ec5\u5982\u6b64\uff0c\u7531\u4e8e\u5b83\u80fdpost Runnable\u5bf9\u8c61\uff0c\u5b83\u8fd8\u80fd\u4e0eLooper\u914d\u5408\u5b9e\u73b0\u7ecf\u5178\u7684Pipeline Thread(\u6d41\u6c34\u7ebf\u7ebf\u7a0b)\u6a21\u5f0f\u3002\u8bf7\u53c2\u8003\u6b64\u6587<\/span>                                \u300aAndroid Guts: Intro to Loopers and Handlers\u300b<\/a><\/p>\n

                                \u5c01\u88c5\u4efb\u52a1 Message<\/b><\/span><\/p>\n

                                \u5728\u6574\u4e2a\u6d88\u606f\u5904\u7406\u673a\u5236\u4e2d\uff0cmessage\u53c8\u53ebtask\uff0c\u5c01\u88c5\u4e86\u4efb\u52a1\u643a\u5e26\u7684\u4fe1\u606f\u548c\u5904\u7406\u8be5\u4efb\u52a1\u7684handler\u3002message\u7684\u7528\u6cd5\u6bd4\u8f83\u7b80\u5355\uff0c\u8fd9\u91cc\u4e0d\u505a\u603b\u7ed3\u4e86\u3002\u4f46\u662f\u6709\u8fd9\u4e48\u51e0\u70b9\u9700\u8981\u6ce8\u610f\uff08\u5f85\u8865\u5145\uff09\uff1a<\/span>
                                \n1.\u5c3d\u7ba1Message\u6709public\u7684\u9ed8\u8ba4\u6784\u9020\u65b9\u6cd5\uff0c\u4f46\u662f\u4f60\u5e94\u8be5\u901a\u8fc7Message.obtain()\u6765\u4ece\u6d88\u606f\u6c60\u4e2d\u83b7\u5f97\u7a7a\u6d88\u606f\u5bf9\u8c61\uff0c\u4ee5\u8282\u7701\u8d44\u6e90\u3002<\/span>
                                \n2.\u5982\u679c\u4f60\u7684message\u53ea\u9700\u8981\u643a\u5e26\u7b80\u5355\u7684int\u4fe1\u606f\uff0c\u8bf7\u4f18\u5148\u4f7f\u7528Message.arg1\u548cMessage.arg2\u6765\u4f20\u9012\u4fe1\u606f\uff0c\u8fd9\u6bd4\u7528Bundle\u66f4\u7701\u5185\u5b58<\/span>
                                \n3.\u64c5\u7528message.what\u6765\u6807\u8bc6\u4fe1\u606f\uff0c\u4ee5\u4fbf\u7528\u4e0d\u540c\u65b9\u5f0f\u5904\u7406message\u3002<\/span><\/p>\n

                                \u5176\u5b83\u7406\u89e3<\/strong><\/p>\n

                                 <\/p>\n

                                \"\"<\/span><\/span><\/p>\n

                                 <\/p>\n

                                Message Queue<\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0 \u5728\u5355\u7ebf\u7a0b\u6a21\u578b\u4e0b\uff0c\u4e3a\u4e86\u89e3\u51b3\u7c7b\u4f3c\u7684\u95ee\u9898\uff0cAndroid<\/span>\u8bbe\u8ba1\u4e86\u4e00\u4e2a<\/span>Message Queue(<\/span>\u6d88\u606f\u961f\u5217<\/span>)<\/span>\uff0c \u7ebf\u7a0b\u95f4\u53ef\u4ee5\u901a\u8fc7\u8be5<\/span>Message Queue<\/span>\u5e76\u7ed3\u5408<\/span>Handler<\/span>\u548c<\/span>Looper<\/span>\u7ec4\u4ef6\u8fdb\u884c\u4fe1\u606f\u4ea4\u6362\u3002\u4e0b\u9762\u5c06\u5bf9\u5b83\u4eec\u8fdb\u884c\u5206\u522b\u4ecb\u7ecd\uff1a<\/span><\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a01. Message<\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0Message\u6d88\u606f\uff0c\u7406\u89e3\u4e3a\u7ebf\u7a0b\u95f4\u4ea4\u6d41\u7684\u4fe1\u606f\uff0c\u5904\u7406\u6570\u636e\u540e\u53f0\u7ebf\u7a0b\u9700\u8981\u66f4\u65b0<\/span>UI<\/span>\uff0c\u5219\u53d1\u9001<\/span>Message<\/span>\u5185\u542b\u4e00\u4e9b\u6570\u636e\u7ed9<\/span>UI<\/span>\u7ebf\u7a0b\u3002<\/span><\/span><\/span><\/p>\n

                                \u00a0\u00a0\u00a0\u00a02. Handler<\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0Handler\u5904\u7406\u8005\uff0c\u662f<\/span>Message<\/span>\u7684\u4e3b\u8981\u5904\u7406\u8005\uff0c\u8d1f\u8d23<\/span>Message<\/span>\u7684\u53d1\u9001\uff0c<\/span>Message<\/span>\u5185\u5bb9\u7684\u6267\u884c\u5904\u7406\u3002\u540e\u53f0\u7ebf\u7a0b\u5c31\u662f\u901a\u8fc7\u4f20\u8fdb\u6765\u7684<\/span>Handler<\/span>\u5bf9\u8c61\u5f15\u7528\u6765<\/span>sendMessage(Message)<\/span>\u3002\u800c\u4f7f\u7528<\/span>Handler<\/span>\uff0c\u9700\u8981<\/span>implement <\/span>\u8be5\u7c7b\u7684 <\/span>handleMessage(Message)<\/span>\u65b9\u6cd5\uff0c\u5b83\u662f\u5904\u7406\u8fd9\u4e9b<\/span>Message<\/span>\u7684\u64cd\u4f5c\u5185\u5bb9\uff0c\u4f8b\u5982<\/span>Update UI<\/span>\u3002\u901a\u5e38\u9700\u8981\u5b50\u7c7b\u5316<\/span>Handler<\/span>\u6765\u5b9e\u73b0<\/span>handleMessage<\/span>\u65b9\u6cd5\u3002<\/span><\/span><\/span><\/p>\n

                                \u00a0\u00a0\u00a0\u00a03. Message Queue<\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0Message Queue\u6d88\u606f\u961f\u5217\uff0c\u7528\u6765\u5b58\u653e\u901a\u8fc7<\/span>Handler<\/span>\u53d1\u5e03\u7684\u6d88\u606f\uff0c\u6309\u7167\u5148\u8fdb\u5148\u51fa\u6267\u884c\u3002<\/span><\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0\u6bcf\u4e2amessage queue<\/span>\u90fd\u4f1a\u6709\u4e00\u4e2a\u5bf9\u5e94\u7684<\/span>Handler<\/span>\u3002<\/span>Handler<\/span>\u4f1a\u5411<\/span>message queue<\/span>\u901a\u8fc7\u4e24\u79cd\u65b9\u6cd5\u53d1\u9001\u6d88\u606f\uff1a<\/span>sendMessage<\/span>\u6216<\/span>post<\/span>\u3002\u8fd9\u4e24\u79cd\u6d88\u606f\u90fd\u4f1a\u63d2\u5728<\/span>message queue<\/span>\u961f\u5c3e\u5e76\u6309\u5148\u8fdb\u5148\u51fa\u6267\u884c\u3002\u4f46\u901a\u8fc7\u8fd9\u4e24\u79cd\u65b9\u6cd5\u53d1\u9001\u7684\u6d88\u606f\u6267\u884c\u7684\u65b9\u5f0f\u7565\u6709\u4e0d\u540c\uff1a\u901a\u8fc7<\/span>sendMessage<\/span>\u53d1\u9001\u7684\u662f\u4e00\u4e2a<\/span>message<\/span>\u5bf9\u8c61<\/span>,<\/span>\u4f1a\u88ab<\/span>Handler<\/span>\u7684<\/span>handleMessage()<\/span>\u51fd\u6570\u5904\u7406\uff1b\u800c\u901a\u8fc7<\/span>post<\/span>\u65b9\u6cd5\u53d1\u9001\u7684\u662f\u4e00\u4e2a<\/span>runnable<\/span>\u5bf9\u8c61\uff0c\u5219\u4f1a\u81ea\u5df1\u6267\u884c\u3002<\/span><\/span><\/span><\/p>\n

                                \u00a0\u00a0\u00a0\u00a04. Looper<\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0Looper\u662f\u6bcf\u6761\u7ebf\u7a0b\u91cc\u7684<\/span>Message Queue<\/span>\u7684\u7ba1\u5bb6\u3002<\/span>Android<\/span>\u6ca1\u6709<\/span>Global<\/span>\u7684<\/span>Message Queue<\/span>\uff0c\u800c<\/span>Android<\/span>\u4f1a\u81ea\u52a8\u66ff\u4e3b\u7ebf\u7a0b<\/span>(UI<\/span>\u7ebf\u7a0b<\/span>)<\/span>\u5efa\u7acb<\/span>Message Queue<\/span>\uff0c\u4f46\u5728\u5b50\u7ebf\u7a0b\u91cc\u5e76\u6ca1\u6709\u5efa\u7acb<\/span>Message Queue<\/span>\u3002\u6240\u4ee5\u8c03\u7528<\/span>Looper.getMainLooper()<\/span>\u5f97\u5230\u7684\u4e3b\u7ebf\u7a0b\u7684<\/span>Looper<\/span>\u4e0d\u4e3a<\/span>NULL<\/span>\uff0c\u4f46\u8c03\u7528<\/span>Looper.myLooper()<\/span>\u5f97\u5230\u5f53\u524d\u7ebf\u7a0b\u7684<\/span>Looper<\/span>\u5c31\u6709\u53ef\u80fd\u4e3a<\/span>NULL<\/span>\u3002<\/span><\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0\u5bf9\u4e8e\u5b50\u7ebf\u7a0b\u4f7f\u7528Looper<\/span>\uff0c<\/span>API Doc<\/span>\u63d0\u4f9b\u4e86\u6b63\u786e\u7684\u4f7f\u7528\u65b9\u6cd5\uff1a<\/span><\/span><\/span>
                                \nclass LooperThread extends Thread { <\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0public Handler mHandler; <\/span><\/span><\/p>\n

                                \u00a0\u00a0\u00a0\u00a0public void run() { <\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Looper.prepare(); \/\/\u521b\u5efa\u672c\u7ebf\u7a0b\u7684<\/span>Looper<\/span>\u5e76\u521b\u5efa\u4e00\u4e2a<\/span>MessageQueue<\/span><\/span><\/span><\/p>\n

                                \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0mHandler = new Handler() { <\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0public void handleMessage(Message msg) { <\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ process incoming messages here <\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0} <\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}; <\/span><\/span>
                                \n\u00a0\u00a0 <\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Looper.loop(); \/\/\u5f00\u59cb\u8fd0\u884c<\/span>Looper,<\/span>\u76d1\u542c<\/span>Message Queue <\/span><\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0} <\/span><\/span>
                                \n} <\/span><\/span><\/p>\n

                                \u00a0\u00a0\u00a0\u00a0\u8fd9\u4e2aMessage<\/span>\u673a\u5236\u7684\u5927\u6982\u6d41\u7a0b\uff1a<\/span><\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a01. \u5728<\/span>Looper.loop()<\/span>\u65b9\u6cd5\u8fd0\u884c\u5f00\u59cb\u540e\uff0c\u5faa\u73af\u5730\u6309\u7167\u63a5\u6536\u987a\u5e8f\u53d6\u51fa<\/span>Message Queue<\/span>\u91cc\u9762\u7684\u975e<\/span>NULL<\/span>\u7684<\/span>Message<\/span>\u3002<\/span><\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a02. \u4e00\u5f00\u59cb<\/span>Message Queue<\/span>\u91cc\u9762\u7684<\/span>Message<\/span>\u90fd\u662f<\/span>NULL<\/span>\u7684\u3002\u5f53<\/span>Handler.sendMessage(Message)<\/span>\u5230<\/span>Message Queue<\/span>\uff0c\u8be5\u51fd\u6570\u91cc\u9762\u8bbe\u7f6e\u4e86\u90a3\u4e2a<\/span>Message<\/span>\u5bf9\u8c61\u7684<\/span>target<\/span>\u5c5e\u6027\u662f\u5f53\u524d\u7684<\/span>Handler<\/span>\u5bf9\u8c61\u3002\u968f\u540e<\/span>Looper<\/span>\u53d6\u51fa\u4e86\u90a3\u4e2a<\/span>Message<\/span>\uff0c\u5219\u8c03\u7528\u8be5<\/span>Message<\/span>\u7684<\/span>target<\/span>\u6307\u5411\u7684<\/span>Hander<\/span>\u7684<\/span>dispatchMessage<\/span>\u51fd\u6570\u5bf9<\/span>Message<\/span>\u8fdb\u884c\u5904\u7406\u3002<\/span><\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0\u5728dispatchMessage<\/span>\u65b9\u6cd5\u91cc\uff0c\u5982\u4f55\u5904\u7406<\/span>Message<\/span>\u5219\u7531\u7528\u6237\u6307\u5b9a\uff0c\u4e09\u4e2a\u5224\u65ad\uff0c\u4f18\u5148\u7ea7\u4ece\u9ad8\u5230\u4f4e\uff1a<\/span><\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a01) Message\u91cc\u9762\u7684<\/span>Callback<\/span>\uff0c\u4e00\u4e2a\u5b9e\u73b0\u4e86<\/span>Runnable<\/span>\u63a5\u53e3\u7684\u5bf9\u8c61\uff0c\u5176\u4e2d<\/span>run<\/span>\u51fd\u6570\u505a\u5904\u7406\u5de5\u4f5c\uff1b<\/span><\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a02) Handler\u91cc\u9762\u7684<\/span>mCallback<\/span>\u6307\u5411\u7684\u4e00\u4e2a\u5b9e\u73b0\u4e86<\/span>Callback<\/span>\u63a5\u53e3\u7684\u5bf9\u8c61\uff0c\u7531\u5176<\/span>handleMessage<\/span>\u8fdb\u884c\u5904\u7406\uff1b<\/span><\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a03) \u5904\u7406\u6d88\u606f<\/span>Handler<\/span>\u5bf9\u8c61\u5bf9\u5e94\u7684\u7c7b\u7ee7\u627f\u5e76\u5b9e\u73b0\u4e86\u5176\u4e2d<\/span>handleMessage<\/span>\u51fd\u6570\uff0c\u901a\u8fc7\u8fd9\u4e2a\u5b9e\u73b0\u7684<\/span>handleMessage<\/span>\u51fd\u6570\u5904\u7406\u6d88\u606f\u3002<\/span><\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a0\u7531\u6b64\u53ef\u89c1\uff0c\u6211\u4eec\u5b9e\u73b0\u7684handleMessage<\/span>\u65b9\u6cd5\u662f\u4f18\u5148\u7ea7\u6700\u4f4e\u7684\uff01<\/span><\/span><\/span>
                                \n\u00a0\u00a0\u00a0\u00a03. Handler\u5904\u7406\u5b8c\u8be5<\/span>Message (update UI) <\/span>\u540e\uff0c<\/span>Looper<\/span>\u5219\u8bbe\u7f6e\u8be5<\/span>Message<\/span>\u4e3a<\/span>NULL<\/span>\uff0c\u4ee5\u4fbf\u56de\u6536\uff01<\/span><\/span><\/span><\/p>\n

                                 <\/p>\n

                                \u539f\u6587\u51fa\u5904:android\u7684\u6d88\u606f\u5904\u7406\u673a\u5236\uff08\u56fe+\u6e90\u7801\u5206\u6790\uff09\u2014\u2014Looper,Handler,Message<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

                                android\u7684\u6d88\u606f\u5904\u7406\u6709\u4e09\u4e2a\u6838\u5fc3\u7c7b\uff1aLooper,Handler\u548cMessage\u3002\u5176\u5b9e\u8fd8\u6709\u4e00\u4e2aMessage […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[3],"tags":[],"_links":{"self":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/1082"}],"collection":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1082"}],"version-history":[{"count":2,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/1082\/revisions"}],"predecessor-version":[{"id":1140,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/1082\/revisions\/1140"}],"wp:attachment":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1082"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1082"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1082"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}