{"id":1209,"date":"2016-02-07T21:25:55","date_gmt":"2016-02-07T13:25:55","guid":{"rendered":"https:\/\/ai.zhousir.top\/?p=1209"},"modified":"2026-08-15T17:01:47","modified_gmt":"2026-08-15T09:01:47","slug":"android-view%e6%80%bb%e7%bb%93","status":"publish","type":"post","link":"https:\/\/ai.zhousir.top\/?p=1209","title":{"rendered":"Android View\u603b\u7ed3"},"content":{"rendered":"

\"\"<\/a><\/h2>\n

\u5173\u4e8eAndroid View\u63a7\u4ef6<\/h2>\n

Android\u4e2d\u63a7\u4ef6\u5927\u81f4\u88ab\u5206\u4e3a\u4e24\u7c7bViewGroup,View\u3002ViewGroup\u4f5c\u4e3a\u5bb9\u5668\u7ba1\u7406View\u3002Android\u89c6\u56fe\uff0c\u662f\u7c7b\u4f3c\u4e8eDom\u6811\u7684\u67b6\u6784\u3002\u7236\u89c6\u56fe\u8d1f\u8d23\u6d4b\u91cf\u5b9a\u4f4d\u7ed8\u5236\u7b49\u64cd\u4f5c\u3002\u6211\u4eec\u7ecf\u5e38\u5728\u7528\u7684findViewById<\/code>\u65b9\u6cd5\u4ee3\u4ef7\u6602\u8d35\u7684\u539f\u56e0\uff0c\u5c31\u662f\u56e0\u4e3a\u4ed6\u8d1f\u8d23\u81f3\u4e0a\u800c\u4e0b\u904d\u5386\u6574\u68f5\u63a7\u4ef6\u6811\uff0c\u6765\u5bfb\u627eView\u5b9e\u4f8b\uff0c\u5728\u91cd\u590d\u64cd\u4f5c\u4e2d\u5c3d\u91cf\u5c11\u7528\u3002\u73b0\u5728\u5728\u7528\u7684\u5f88\u591a\u63a7\u4ef6\u90fd\u662f\u76f4\u63a5\u6216\u8005\u95f4\u63a5\u7ee7\u627f\u81eaView\u7684\uff0c\u5982\u4e0b\u56fe\u3002<\/p>\n

Android UI\u754c\u9762\u67b6\u6784<\/h2>\n

\u6bcf\u4e2aActivity\u5305\u542b\u4e00\u4e2aPhoneWindow<\/code>\u5bf9\u8c61\uff0cPhoneWindow<\/code>\u8bbe\u7f6eDecorView<\/code>\u4e3a\u5e94\u7528\u7a97\u53e3\u7684\u6839\u89c6\u56fe\u3002\u5728\u91cc\u9762\u5c31\u662f\u719f\u6089\u7684TitleView<\/code>\u548cContentView<\/code>,\u6ca1\u9519\uff0c\u5e73\u65f6\u4f7f\u7528\u7684setContentView()<\/code>\u5c31\u662f\u8bbe\u7f6e\u7684ContentView<\/code>\u3002<\/p>\n

Android\u662f\u5982\u4f55\u7ed8\u5236View\u7684\uff1f<\/h2>\n

\u5f53\u4e00\u4e2aActivity\u542f\u52a8\u65f6\uff0c\u4f1a\u88ab\u8981\u6c42\u7ed8\u5236\u51fa\u5b83\u7684\u5e03\u5c40\u3002Android\u6846\u67b6\u4f1a\u5904\u7406\u8fd9\u4e2a\u8bf7\u6c42\uff0c\u5f53\u7136\u524d\u63d0\u662fActivity\u63d0\u4f9b\u4e86\u5408\u7406\u7684\u5e03\u5c40\u3002\u7ed8\u5236\u4ece\u6839\u89c6\u56fe\u5f00\u59cb\uff0c\u4ece\u4e0a\u81f3\u4e0b\u904d\u5386\u6574\u68f5\u89c6\u56fe\u6811\uff0c\u6bcf\u4e00\u4e2aViewGroup<\/code>\u8d1f\u8d23\u8ba9\u81ea\u5df1\u7684\u5b50View<\/code>\u88ab\u7ed8\u5236\uff0c\u6bcf\u4e00\u4e2aView<\/code>\u8d1f\u8d23\u7ed8\u5236\u81ea\u5df1\uff0c\u901a\u8fc7draw()<\/code>\u65b9\u6cd5.\u7ed8\u5236\u8fc7\u7a0b\u5206\u4e09\u6b65\u8d70\u3002<\/p>\n

    \n
  • Measure<\/li>\n
  • Layout<\/li>\n
  • Draw<\/li>\n<\/ul>\n

    \u6574\u4e2a\u7ed8\u5236\u6d41\u7a0b\u662f\u5728ViewRoot<\/code>\u4e2d\u7684performTraversals()<\/code>\u65b9\u6cd5\u5c55\u5f00\u7684\u3002\u90e8\u5206\u6e90\u4ee3\u7801\u5982\u4e0b\u3002<\/p>\n

    \n\n\n\n
    \n
    1<\/span>\n2<\/span>\n3<\/span>\n4<\/span>\n5<\/span>\n6<\/span>\n7<\/span>\n8<\/span>\n9<\/span>\n10<\/span>\n11<\/span>\n12<\/span>\n13<\/span>\n14<\/span><\/pre>\n<\/td>\n
    		\n
    private<\/span> void<\/span> performTraversals<\/span>()<\/span> <\/span>{<\/span>\n    ......<\/span>\n    \/\/\u6700\u5916\u5c42\u7684\u6839\u89c6\u56fe\u7684widthMeasureSpec\u548cheightMeasureSpec\u7531\u6765<\/span><\/span>\n    \/\/lp.width\u548clp.height\u5728\u521b\u5efaViewGroup\u5b9e\u4f8b\u65f6\u7b49\u4e8eMATCH_PARENT<\/span><\/span>\n    int<\/span> childWidthMeasureSpec = getRootMeasureSpec(mWidth, lp.width);<\/span>\n    int<\/span> childHeightMeasureSpec = getRootMeasureSpec(mHeight, lp.height);<\/span>\n    ......<\/span>\n    mView.measure(childWidthMeasureSpec, childHeightMeasureSpec);<\/span>\n    ......<\/span>\n    mView.layout(0<\/span>, 0<\/span>, mView.getMeasuredWidth(), mView.getMeasuredHeight());<\/span>\n    ......<\/span>\n    mView.draw(canvas);<\/span>\n    ......<\/span>\n}<\/span><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n
    \u5728\u7ed8\u5236\u4e4b\u524d\u5f53\u7136\u8981\u77e5\u9053view\u7684\u5c3a\u5bf8\u548c\u7ed8\u5236\u3002\u6240\u4ee5\u5148\u8fdb\u884cmeasu<\/code>\u548clayout<\/code>\uff08\u6d4b\u91cf\u548c\u5b9a\u4f4d\uff09\uff0c\u5982\u4e0b\u56fe\u3002<\/p>\n
    Measure\u8fc7\u7a0b<\/h2>\n
    \n\n\n\n
    \n
    1<\/span>\n2<\/span>\n3<\/span>\n4<\/span>\n5<\/span>\n6<\/span>\n7<\/span>\n8<\/span><\/pre>\n<\/td>\n
    		\n
    public<\/span> final<\/span> void<\/span> measure<\/span>(int<\/span> widthMeasureSpec, int<\/span> heightMeasureSpec)<\/span> <\/span>{  <\/span>\n    \/\/....  <\/span><\/span>\n  \n    \/\/\u56de\u8c03onMeasure()\u65b9\u6cd5    <\/span><\/span>\n    onMeasure(widthMeasureSpec, heightMeasureSpec);  <\/span>\n     \n    \/\/more  <\/span><\/span>\n}<\/span><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n
    \u8ba1\u7b97view\u7684\u5b9e\u9645\u5927\u5c0f\uff0c\u83b7\u5f97\u9ad8\u5bbd\u5b58\u5165mMeasuredHeight<\/code>\u548cmMeasureWidth<\/code>\uff0cmeasure(int, int)<\/code>\u4f20\u5165\u7684\u4e24\u4e2a\u53c2\u6570\u3002MeasureSpec<\/code>\u662f\u4e00\u4e2a32\u4f4dint\u503c\uff0c\u9ad82\u4f4d\u4e3a\u6d4b\u91cf\u7684\u6a21\u5f0f\uff0c\u4f4e30\u4f4d\u4e3a\u6d4b\u91cf\u7684\u5927\u5c0f\u3002\u6d4b\u91cf\u7684\u6a21\u5f0f\u53ef\u4ee5\u5206\u4e3a\u4ee5\u4e0b\u4e09\u79cd\u3002<\/p>\n