{"id":3043,"date":"2020-09-16T20:41:23","date_gmt":"2020-09-16T12:41:23","guid":{"rendered":"http:\/\/www.yuguoxy.com\/geekhome\/?p=3043"},"modified":"2026-08-18T12:35:33","modified_gmt":"2026-08-18T04:35:33","slug":"%e6%b5%8f%e8%a7%88%e5%99%a8-file-%e5%af%b9%e8%b1%a1%ef%bc%8cfilelist-%e5%af%b9%e8%b1%a1%ef%bc%8cfilereader-%e5%af%b9%e8%b1%a1","status":"publish","type":"post","link":"https:\/\/ai.zhousir.top\/?p=3043","title":{"rendered":"\u6d4f\u89c8\u5668\u2014File \u5bf9\u8c61\uff0cFileList \u5bf9\u8c61\uff0cFileReader \u5bf9\u8c61"},"content":{"rendered":"<section id=\"wenyan\" style=\"font-family: system-ui, 'Apple Color Emoji', 'Segoe UI', 'Segoe UI Symbol', 'Noto Sans', Roboto, sans-serif; line-height: 1.75; font-size: 16px; color: #000000; caret-color: #000000;\" data-provider=\"WenYan\">\n<p style=\"margin: 1em 0px;\">\u6d4f\u89c8\u5668\u91cc\u8bfb\u5199\u672c\u5730\u6587\u4ef6\uff0c\u5e38\u7528\u4e09\u4e2a\u5bf9\u8c61\uff1a<strong style=\"color: #4870ac;\">File<\/strong>\u3001<strong style=\"color: #4870ac;\">FileList<\/strong>\u3001<strong style=\"color: #4870ac;\">FileReader<\/strong>\u3002File \u7ee7\u627f Blob\uff0c\u51fa\u73b0\u5728\u6587\u4ef6\u9009\u62e9\u6846\u548c\u62d6\u62fd\u91cc\uff1bFileList \u662f\u4e00\u7ec4 File\uff1bFileReader \u8d1f\u8d23\u628a\u5185\u5bb9\u8bfb\u6210\u6587\u672c\u3001\u4e8c\u8fdb\u5236\u6216 Data URL\u3002<\/p>\n<p style=\"margin: 1em 0px;\">\u6700\u5e38\u89c1\u5165\u53e3\u662f <code style=\"font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; color: #4870ac; font-size: 0.9em; font-weight: normal; overflow-wrap: break-word; padding: 2px 4px; border-radius: 3px; margin: 2px; background-color: #f6f8fa; word-break: break-all;\">&lt;input type=\"file\"&gt;<\/code>\uff1a\u7528\u6237\u9009\u4e2d\u540e\uff0c\u6d4f\u89c8\u5668\u751f\u6210\u6570\u7ec4\uff0c\u6bcf\u4e2a\u6210\u5458\u90fd\u662f File \u5b9e\u4f8b\u3002<\/p>\n<table style=\"display: table; text-align: left; overflow: auto; border-collapse: collapse; margin: 1.4em auto; max-width: 100%; table-layout: fixed; overflow-wrap: break-word; word-break: break-all;\" width=\"800\">\n<thead>\n<tr>\n<th style=\"border: 1px solid #d9dfe4; padding: 9px 12px; font-size: 0.75em; line-height: 22px; vertical-align: top; text-align: center; font-weight: bold; color: #4870ac; background: #f7f7f7;\">\u5bf9\u8c61<\/th>\n<th style=\"border: 1px solid #d9dfe4; padding: 9px 12px; font-size: 0.75em; line-height: 22px; vertical-align: top; text-align: center; font-weight: bold; color: #4870ac; background: #f7f7f7;\">\u662f\u4ec0\u4e48<\/th>\n<th style=\"border: 1px solid #d9dfe4; padding: 9px 12px; font-size: 0.75em; line-height: 22px; vertical-align: top; text-align: center; font-weight: bold; color: #4870ac; background: #f7f7f7;\">\u5e38\u89c1\u5165\u53e3<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border: 1px solid #d9dfe4; padding: 9px 12px; font-size: 0.75em; line-height: 22px; vertical-align: top;\">File<\/td>\n<td style=\"border: 1px solid #d9dfe4; padding: 9px 12px; font-size: 0.75em; line-height: 22px; vertical-align: top;\">\u7279\u6b8a\u7684 Blob\uff0c\u5e26\u6587\u4ef6\u540d\u548c\u4fee\u6539\u65f6\u95f4<\/td>\n<td style=\"border: 1px solid #d9dfe4; padding: 9px 12px; font-size: 0.75em; line-height: 22px; vertical-align: top;\">input.files[0]\u3001\u624b\u52a8 new File<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9dfe4; padding: 9px 12px; font-size: 0.75em; line-height: 22px; vertical-align: top;\">FileList<\/td>\n<td style=\"border: 1px solid #d9dfe4; padding: 9px 12px; font-size: 0.75em; line-height: 22px; vertical-align: top;\">\u7c7b\u6570\u7ec4\uff0c\u4e00\u7ec4 File<\/td>\n<td style=\"border: 1px solid #d9dfe4; padding: 9px 12px; font-size: 0.75em; line-height: 22px; vertical-align: top;\">input.files\u3001DataTransfer.files<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9dfe4; padding: 9px 12px; font-size: 0.75em; line-height: 22px; vertical-align: top;\">FileReader<\/td>\n<td style=\"border: 1px solid #d9dfe4; padding: 9px 12px; font-size: 0.75em; line-height: 22px; vertical-align: top;\">\u5f02\u6b65\u8bfb\u53d6 File\/Blob \u5185\u5bb9<\/td>\n<td style=\"border: 1px solid #d9dfe4; padding: 9px 12px; font-size: 0.75em; line-height: 22px; vertical-align: top;\">readAsText \/ DataURL \/ ArrayBuffer<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2 style=\"padding: 1px 12.5px; color: #ffffff; margin: 1.2em 0px 1em; border-radius: 4px; display: inline-block; background-color: #4870ac; font-size: 1.3em;\">\u4e00\u3001File \u5bf9\u8c61<\/h2>\n<p style=\"margin: 1em 0px;\">File \u7528\u6765\u8bfb\u5199\u6587\u4ef6\u4fe1\u606f\u3002\u51e1\u662f\u80fd\u7528 Blob \u7684\u5730\u65b9\u90fd\u80fd\u7528\u5b83\u3002<\/p>\n<pre style=\"overflow: auto hidden; word-break: normal; white-space: pre; tab-size: 2; border-radius: 5px; line-height: 2; margin: 1em 0.5em; padding: 0.5em; box-shadow: rgba(0, 0, 0, 0.55) 0px 1px 5px; font-size: 12px; background: #002b36; max-width: 100%; overflow-wrap: normal;\"><code class=\"hljs\" style=\"word-break: normal; white-space: nowrap; tab-size: 2; font-size: 12px; font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; display: block; overflow-x: auto; margin: 0.5em; padding: 3px 5px; color: #93a1a1; background: #002b36; overflow-wrap: normal;\">\/\/ HTML \u4ee3\u7801\u5982\u4e0b\n\/\/ &lt;input id=\"fileItem\" type=\"file\">\nvar file = document.getElementById('fileItem').files[0];\nfile instanceof File \/\/ true<\/code><\/pre>\n<p style=\"margin: 1em 0px;\">\u4e0a\u9762\u7684 <code style=\"font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; color: #4870ac; font-size: 0.9em; font-weight: normal; overflow-wrap: break-word; padding: 2px 4px; border-radius: 3px; margin: 2px; background-color: #f6f8fa; word-break: break-all;\">file<\/code> \u662f\u7528\u6237\u9009\u4e2d\u7684\u7b2c\u4e00\u4e2a\u6587\u4ef6\uff0c\u5b83\u662f File \u7684\u5b9e\u4f8b\u3002<\/p>\n<h3 style=\"padding: 0px; color: #4870ac; margin: 1.2em 0px 1em; font-size: 1.3em;\">1.1 \u6784\u9020\u51fd\u6570<\/h3>\n<p style=\"margin: 1em 0px;\">\u6d4f\u89c8\u5668\u539f\u751f\u63d0\u4f9b <code style=\"font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; color: #4870ac; font-size: 0.9em; font-weight: normal; overflow-wrap: break-word; padding: 2px 4px; border-radius: 3px; margin: 2px; background-color: #f6f8fa; word-break: break-all;\">File()<\/code>\uff1a<\/p>\n<pre style=\"overflow: auto hidden; word-break: normal; white-space: pre; tab-size: 2; border-radius: 5px; line-height: 2; margin: 1em 0.5em; padding: 0.5em; box-shadow: rgba(0, 0, 0, 0.55) 0px 1px 5px; font-size: 12px; background: #002b36; max-width: 100%; overflow-wrap: normal;\"><code class=\"hljs\" style=\"word-break: normal; white-space: nowrap; tab-size: 2; font-size: 12px; font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; display: block; overflow-x: auto; margin: 0.5em; padding: 3px 5px; color: #93a1a1; background: #002b36; overflow-wrap: normal;\">new File(array, name [, options])<\/code><\/pre>\n<p style=\"margin: 1em 0px;\">\u4e09\u4e2a\u53c2\u6570\uff1a<\/p>\n<ul style=\"padding-left: 1rem; margin-left: 1rem; font-size: 0.9rem; list-style-type: disc;\">\n<li>\n<section>array\uff1a\u6570\u7ec4\uff0c\u6210\u5458\u53ef\u4ee5\u662f\u4e8c\u8fdb\u5236\u5bf9\u8c61\u6216\u5b57\u7b26\u4e32\uff0c\u8868\u793a\u6587\u4ef6\u5185\u5bb9\u3002<\/section>\n<\/li>\n<li>\n<section>name\uff1a\u5b57\u7b26\u4e32\uff0c\u6587\u4ef6\u540d\u6216\u6587\u4ef6\u8def\u5f84\u3002<\/section>\n<\/li>\n<li>\n<section>options\uff1a\u53ef\u9009\u914d\u7f6e\u5bf9\u8c61\u3002<\/section>\n<\/li>\n<\/ul>\n<p style=\"margin: 1em 0px;\">\u914d\u7f6e\u5bf9\u8c61\u53ef\u8bbe\u4e24\u4e2a\u5c5e\u6027\uff1a<\/p>\n<ul style=\"padding-left: 1rem; margin-left: 1rem; font-size: 0.9rem; list-style-type: disc;\">\n<li>\n<section>type\uff1aMIME \u7c7b\u578b\uff0c\u9ed8\u8ba4\u7a7a\u5b57\u7b26\u4e32\u3002<\/section>\n<\/li>\n<li>\n<section>lastModified\uff1a\u65f6\u95f4\u6233\uff0c\u4e0a\u6b21\u4fee\u6539\u65f6\u95f4\uff0c\u9ed8\u8ba4\u4e3a Date.now()\u3002<\/section>\n<\/li>\n<\/ul>\n<pre style=\"overflow: auto hidden; word-break: normal; white-space: pre; tab-size: 2; border-radius: 5px; line-height: 2; margin: 1em 0.5em; padding: 0.5em; box-shadow: rgba(0, 0, 0, 0.55) 0px 1px 5px; font-size: 12px; background: #002b36; max-width: 100%; overflow-wrap: normal;\"><code class=\"hljs\" style=\"word-break: normal; white-space: nowrap; tab-size: 2; font-size: 12px; font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; display: block; overflow-x: auto; margin: 0.5em; padding: 3px 5px; color: #93a1a1; background: #002b36; overflow-wrap: normal;\">var file = new File(\n  ['foo'],\n  'foo.txt',\n  {\n    type: 'text\/plain',\n  }\n);<\/code><\/pre>\n<h3 style=\"padding: 0px; color: #4870ac; margin: 1.2em 0px 1em; font-size: 1.3em;\">1.2 \u5b9e\u4f8b\u5c5e\u6027\u548c\u5b9e\u4f8b\u65b9\u6cd5<\/h3>\n<ul style=\"padding-left: 1rem; margin-left: 1rem; font-size: 0.9rem; list-style-type: disc;\">\n<li>\n<section>File.lastModified\uff1a\u6700\u540e\u4fee\u6539\u65f6\u95f4<\/section>\n<\/li>\n<li>\n<section>File.name\uff1a\u6587\u4ef6\u540d\u6216\u6587\u4ef6\u8def\u5f84<\/section>\n<\/li>\n<li>\n<section>File.size\uff1a\u6587\u4ef6\u5927\u5c0f\uff08\u5355\u4f4d\u5b57\u8282\uff09<\/section>\n<\/li>\n<li>\n<section>File.type\uff1a\u6587\u4ef6\u7684 MIME \u7c7b\u578b<\/section>\n<\/li>\n<\/ul>\n<pre style=\"overflow: auto hidden; word-break: normal; white-space: pre; tab-size: 2; border-radius: 5px; line-height: 2; margin: 1em 0.5em; padding: 0.5em; box-shadow: rgba(0, 0, 0, 0.55) 0px 1px 5px; font-size: 12px; background: #002b36; max-width: 100%; overflow-wrap: normal;\"><code class=\"hljs\" style=\"word-break: normal; white-space: nowrap; tab-size: 2; font-size: 12px; font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; display: block; overflow-x: auto; margin: 0.5em; padding: 3px 5px; color: #93a1a1; background: #002b36; overflow-wrap: normal;\"><\/code><\/pre>\n<pre style=\"overflow: auto hidden; word-break: normal; white-space: pre; tab-size: 2; border-radius: 5px; line-height: 2; margin: 1em 0.5em; padding: 0.5em; box-shadow: rgba(0, 0, 0, 0.55) 0px 1px 5px; font-size: 12px; background: #002b36; max-width: 100%; overflow-wrap: normal;\"><code class=\"hljs\" style=\"word-break: normal; white-space: nowrap; tab-size: 2; font-size: 12px; font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; display: block; overflow-x: auto; margin: 0.5em; padding: 3px 5px; color: #93a1a1; background: #002b36; overflow-wrap: normal;\">var myFile = new File([], 'file.bin', {\n  lastModified: new Date(2018, 1, 1),\n});\nmyFile.lastModified \/\/ 1517414400000\nmyFile.name \/\/ \"file.bin\"\nmyFile.size \/\/ 0\nmyFile.type \/\/ \"\"<\/code><\/pre>\n<p style=\"margin: 1em 0px;\">\u5185\u5bb9\u4e3a\u7a7a\u4e14\u6ca1\u8bbe MIME \u65f6\uff0c<code style=\"font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; color: #4870ac; font-size: 0.9em; font-weight: normal; overflow-wrap: break-word; padding: 2px 4px; border-radius: 3px; margin: 2px; background-color: #f6f8fa; word-break: break-all;\">size<\/code> \u4e3a 0\uff0c<code style=\"font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; color: #4870ac; font-size: 0.9em; font-weight: normal; overflow-wrap: break-word; padding: 2px 4px; border-radius: 3px; margin: 2px; background-color: #f6f8fa; word-break: break-all;\">type<\/code> \u4e3a\u7a7a\u5b57\u7b26\u4e32\u3002File \u6ca1\u6709\u81ea\u5df1\u7684\u5b9e\u4f8b\u65b9\u6cd5\uff0c\u7ee7\u627f Blob \u540e\u53ef\u4ee5\u4f7f\u7528 <code style=\"font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; color: #4870ac; font-size: 0.9em; font-weight: normal; overflow-wrap: break-word; padding: 2px 4px; border-radius: 3px; margin: 2px; background-color: #f6f8fa; word-break: break-all;\">slice()<\/code>\u3002<\/p>\n<h2 style=\"padding: 1px 12.5px; color: #ffffff; margin: 1.2em 0px 1em; border-radius: 4px; display: inline-block; background-color: #4870ac; font-size: 1.3em;\">\u4e8c\u3001FileList \u5bf9\u8c61<\/h2>\n<p style=\"margin: 1em 0px;\">FileList \u662f\u7c7b\u4f3c\u6570\u7ec4\u7684\u5bf9\u8c61\uff0c\u6bcf\u4e2a\u6210\u5458\u90fd\u662f File\uff0c\u4e3b\u8981\u51fa\u73b0\u5728\u4e24\u5904\uff1a<\/p>\n<ul style=\"padding-left: 1rem; margin-left: 1rem; font-size: 0.9rem; list-style-type: disc;\">\n<li>\n<section>\u6587\u4ef6\u63a7\u4ef6\u8282\u70b9\uff08<input type=\"file\" \/>\uff09\u7684 files \u5c5e\u6027\uff0c\u8fd4\u56de\u4e00\u4e2a FileList \u5b9e\u4f8b\u3002<\/section>\n<\/li>\n<li>\n<section>\u62d6\u62c9\u4e00\u7ec4\u6587\u4ef6\u65f6\uff0c\u76ee\u6807\u533a\u7684 DataTransfer.files \u5c5e\u6027\uff0c\u8fd4\u56de\u4e00\u4e2a FileList \u5b9e\u4f8b\u3002<\/section>\n<\/li>\n<\/ul>\n<pre style=\"overflow: auto hidden; word-break: normal; white-space: pre; tab-size: 2; border-radius: 5px; line-height: 2; margin: 1em 0.5em; padding: 0.5em; box-shadow: rgba(0, 0, 0, 0.55) 0px 1px 5px; font-size: 12px; background: #002b36; max-width: 100%; overflow-wrap: normal;\"><code class=\"hljs\" style=\"word-break: normal; white-space: nowrap; tab-size: 2; font-size: 12px; font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; display: block; overflow-x: auto; margin: 0.5em; padding: 3px 5px; color: #93a1a1; background: #002b36; overflow-wrap: normal;\">\/\/ HTML \u4ee3\u7801\u5982\u4e0b\n\/\/ &lt;input id=\"fileItem\" type=\"file\">\nvar files = document.getElementById('fileItem').files;\nfiles instanceof FileList \/\/ true<\/code><\/pre>\n<p style=\"margin: 1em 0px;\">\u5b9e\u4f8b\u5c5e\u6027\u4e3b\u8981\u662f <code style=\"font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; color: #4870ac; font-size: 0.9em; font-weight: normal; overflow-wrap: break-word; padding: 2px 4px; border-radius: 3px; margin: 2px; background-color: #f6f8fa; word-break: break-all;\">length<\/code>\u3002\u5b9e\u4f8b\u65b9\u6cd5\u4e3b\u8981\u662f <code style=\"font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; color: #4870ac; font-size: 0.9em; font-weight: normal; overflow-wrap: break-word; padding: 2px 4px; border-radius: 3px; margin: 2px; background-color: #f6f8fa; word-break: break-all;\">item()<\/code>\uff0c\u63a5\u53d7\u4ece\u96f6\u5f00\u59cb\u7684\u6574\u6570\u3002\u56e0\u4e3a FileList \u50cf\u6570\u7ec4\uff0c<code style=\"font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; color: #4870ac; font-size: 0.9em; font-weight: normal; overflow-wrap: break-word; padding: 2px 4px; border-radius: 3px; margin: 2px; background-color: #f6f8fa; word-break: break-all;\">myFileList[0]<\/code> \u7b49\u540c\u4e8e <code style=\"font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; color: #4870ac; font-size: 0.9em; font-weight: normal; overflow-wrap: break-word; padding: 2px 4px; border-radius: 3px; margin: 2px; background-color: #f6f8fa; word-break: break-all;\">myFileList.item(0)<\/code>\uff0c\u4e00\u822c\u7528\u4e0d\u5230 <code style=\"font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; color: #4870ac; font-size: 0.9em; font-weight: normal; overflow-wrap: break-word; padding: 2px 4px; border-radius: 3px; margin: 2px; background-color: #f6f8fa; word-break: break-all;\">item()<\/code>\u3002<\/p>\n<h2 style=\"padding: 1px 12.5px; color: #ffffff; margin: 1.2em 0px 1em; border-radius: 4px; display: inline-block; background-color: #4870ac; font-size: 1.3em;\">\u4e09\u3001FileReader \u5bf9\u8c61<\/h2>\n<p style=\"margin: 1em 0px;\">FileReader \u8bfb\u53d6 File \u6216 Blob \u91cc\u7684\u6587\u4ef6\u5185\u5bb9\u3002\u539f\u751f\u6784\u9020\u51fd\u6570\uff1a<\/p>\n<pre style=\"overflow: auto hidden; word-break: normal; white-space: pre; tab-size: 2; border-radius: 5px; line-height: 2; margin: 1em 0.5em; padding: 0.5em; box-shadow: rgba(0, 0, 0, 0.55) 0px 1px 5px; font-size: 12px; background: #002b36; max-width: 100%; overflow-wrap: normal;\"><code class=\"hljs\" style=\"word-break: normal; white-space: nowrap; tab-size: 2; font-size: 12px; font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; display: block; overflow-x: auto; margin: 0.5em; padding: 3px 5px; color: #93a1a1; background: #002b36; overflow-wrap: normal;\">var reader = new FileReader();<\/code><\/pre>\n<p style=\"margin: 1em 0px;\">\u5b9e\u4f8b\u5c5e\u6027\uff1a<\/p>\n<ul style=\"padding-left: 1rem; margin-left: 1rem; font-size: 0.9rem; list-style-type: disc;\">\n<li>\n<section>FileReader.error\uff1a\u8bfb\u53d6\u65f6\u4ea7\u751f\u7684\u9519\u8bef\u5bf9\u8c61<\/section>\n<\/li>\n<li>\n<section>FileReader.readyState\uff1a0 \u5c1a\u672a\u52a0\u8f7d\uff0c1 \u6b63\u5728\u52a0\u8f7d\uff0c2 \u52a0\u8f7d\u5b8c\u6210<\/section>\n<\/li>\n<li>\n<section>FileReader.result\uff1a\u5b8c\u6210\u540e\u7684\u5185\u5bb9\uff0c\u53ef\u80fd\u662f\u5b57\u7b26\u4e32\u6216 ArrayBuffer<\/section>\n<\/li>\n<li>\n<section>FileReader.onabort\uff1aabort\uff08\u7528\u6237\u7ec8\u6b62\uff09<\/section>\n<\/li>\n<li>\n<section>FileReader.onerror\uff1aerror\uff08\u8bfb\u53d6\u9519\u8bef\uff09<\/section>\n<\/li>\n<li>\n<section>FileReader.onload\uff1aload\uff08\u5b8c\u6210\uff09\uff0c\u901a\u5e38\u5728\u8fd9\u91cc\u7528 result \u62ff\u5185\u5bb9<\/section>\n<\/li>\n<li>\n<section>FileReader.onloadstart\uff1aloadstart\uff08\u5f00\u59cb\uff09<\/section>\n<\/li>\n<li>\n<section>FileReader.onloadend\uff1aloadend\uff08\u7ed3\u675f\uff09<\/section>\n<\/li>\n<li>\n<section>FileReader.onprogress\uff1aprogress\uff08\u8fdb\u884c\u4e2d\uff09<\/section>\n<\/li>\n<\/ul>\n<p style=\"margin: 1em 0px;\">\u76d1\u542c <code style=\"font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; color: #4870ac; font-size: 0.9em; font-weight: normal; overflow-wrap: break-word; padding: 2px 4px; border-radius: 3px; margin: 2px; background-color: #f6f8fa; word-break: break-all;\">load<\/code> \u7684\u4f8b\u5b50\uff1a<\/p>\n<pre style=\"overflow: auto hidden; word-break: normal; white-space: pre; tab-size: 2; border-radius: 5px; line-height: 2; margin: 1em 0.5em; padding: 0.5em; box-shadow: rgba(0, 0, 0, 0.55) 0px 1px 5px; font-size: 12px; background: #002b36; max-width: 100%; overflow-wrap: normal;\"><code class=\"hljs\" style=\"word-break: normal; white-space: nowrap; tab-size: 2; font-size: 12px; font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; display: block; overflow-x: auto; margin: 0.5em; padding: 3px 5px; color: #93a1a1; background: #002b36; overflow-wrap: normal;\">\/\/ HTML \u4ee3\u7801\u5982\u4e0b\n\/\/ &lt;input type=\"file\" onchange=\"onChange(event)\">\n\nfunction onChange(event) {\n  var file = event.target.files[0];\n  var reader = new FileReader();\n  reader.onload = function (event) {\n    console.log(event.target.result)\n  };\n\n  reader.readAsText(file);\n}<\/code><\/pre>\n<p style=\"margin: 1em 0px;\">\u6587\u4ef6\u63a7\u4ef6\u4e00\u53d8\u5c31\u8bfb\u7b2c\u4e00\u4e2a\u6587\u4ef6\uff0c\u6210\u529f\u5219\u6253\u5370\u5185\u5bb9\u3002\u5b9e\u4f8b\u65b9\u6cd5\uff1a<\/p>\n<ul style=\"padding-left: 1rem; margin-left: 1rem; font-size: 0.9rem; list-style-type: disc;\">\n<li>\n<section>FileReader.abort()\uff1a\u7ec8\u6b62\u8bfb\u53d6\uff0creadyState \u53d8\u6210 2\u3002<\/section>\n<\/li>\n<li>\n<section>FileReader.readAsArrayBuffer()\uff1a\u5b8c\u6210\u540e result \u662f ArrayBuffer\u3002<\/section>\n<\/li>\n<li>\n<section>FileReader.readAsBinaryString()\uff1a\u5b8c\u6210\u540e result \u662f\u539f\u59cb\u4e8c\u8fdb\u5236\u5b57\u7b26\u4e32\u3002<\/section>\n<\/li>\n<li>\n<section>FileReader.readAsDataURL()\uff1a\u5b8c\u6210\u540e result \u662f Data URL\uff08Base64\uff09\u3002\u56fe\u7247\u53ef\u7528\u5230 <img alt=\"\" \/> \u7684 src\u3002\u6ce8\u610f\u4e0d\u80fd\u76f4\u63a5 Base64 \u89e3\u7801\uff0c\u5fc5\u987b\u5148\u5220\u6389\u524d\u7f00 data:*\/*;base64,\u3002<\/section>\n<\/li>\n<li>\n<section>FileReader.readAsText()\uff1a\u5b8c\u6210\u540e result \u662f\u6587\u672c\u3002\u7b2c\u4e00\u4e2a\u53c2\u6570\u662f Blob\uff0c\u7b2c\u4e8c\u4e2a\u53ef\u9009\uff0c\u6587\u672c\u7f16\u7801\uff0c\u9ed8\u8ba4 UTF-8\u3002<\/section>\n<\/li>\n<\/ul>\n<pre style=\"overflow: auto hidden; word-break: normal; white-space: pre; tab-size: 2; border-radius: 5px; line-height: 2; margin: 1em 0.5em; padding: 0.5em; box-shadow: rgba(0, 0, 0, 0.55) 0px 1px 5px; font-size: 12px; background: #002b36; max-width: 100%; overflow-wrap: normal;\"><code class=\"hljs\" style=\"word-break: normal; white-space: nowrap; tab-size: 2; font-size: 12px; font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; display: block; overflow-x: auto; margin: 0.5em; padding: 3px 5px; color: #93a1a1; background: #002b36; overflow-wrap: normal;\">\/* HTML \u4ee3\u7801\u5982\u4e0b\n  &lt;input type=\"file\" onchange=\"previewFile()\">\n  &lt;img src=\"\" height=\"200\">\n*\/\n\nfunction previewFile() {\n  var preview = document.querySelector('img');\n  var file    = document.querySelector('input[type=file]').files[0];\n  var reader  = new FileReader();\n\n  reader.addEventListener('load', function () {\n    preview.src = reader.result;\n  }, false);\n\n  if (file) {\n    reader.readAsDataURL(file);\n  }\n}<\/code><\/pre>\n<p style=\"margin: 1em 0px;\">\u7528\u6237\u9009\u4e2d\u56fe\u7247\u540e\uff0c\u811a\u672c\u8bfb\u6210 Data URL \u8d4b\u7ed9 <code style=\"font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; color: #4870ac; font-size: 0.9em; font-weight: normal; overflow-wrap: break-word; padding: 2px 4px; border-radius: 3px; margin: 2px; background-color: #f6f8fa; word-break: break-all;\">&lt;img&gt;<\/code> \u7684 <code style=\"font-family: Menlo, Monaco, Consolas, 'Liberation Mono', 'Roboto Mono', 'Courier New', 'Microsoft YaHei', monospace; color: #4870ac; font-size: 0.9em; font-weight: normal; overflow-wrap: break-word; padding: 2px 4px; border-radius: 3px; margin: 2px; background-color: #f6f8fa; word-break: break-all;\">src<\/code>\uff0c\u628a\u56fe\u5c55\u793a\u51fa\u6765\u3002<\/p>\n<h3 style=\"padding: 0px; color: #4870ac; margin: 1.2em 0px 1em; font-size: 1.3em;\">\u63a8\u8350\u9605\u8bfb<\/h3>\n<ul style=\"padding-left: 1rem; margin-left: 1rem; font-size: 0.9rem; list-style-type: disc;\">\n<li>\n<section><a href=\"http:\/\/mp.weixin.qq.com\/s?__biz=MjM5MDA2MTI1MA==&amp;mid=2649093681&amp;idx=4&amp;sn=34daa04c9899497ace52bfc854021cb5&amp;chksm=be5bd19c892c588accd866c42c30fee8016fd678f51b7a496fff4da33d1c583c7677f705be0b&amp;scene=21#wechat_redirect\">\u3010JavaScript \u6559\u7a0b\u3011\u6d4f\u89c8\u5668\u6a21\u578b\u2014Cookie<\/a><\/section>\n<\/li>\n<li>\n<section><a href=\"http:\/\/mp.weixin.qq.com\/s?__biz=MjM5MDA2MTI1MA==&amp;mid=2649093610&amp;idx=3&amp;sn=5abf8b0475a45239af3c4df0799de4f5&amp;chksm=be5bd247892c5b51ec79f0e41e74498abaeae605b7699be82ae5b5a365309fd0550f83f7dc25&amp;scene=21#wechat_redirect\">Navigator \u5bf9\u8c61\uff0cScreen \u5bf9\u8c61\u3002<\/a><\/section>\n<\/li>\n<li>\n<section><a href=\"http:\/\/mp.weixin.qq.com\/s?__biz=MjM5MDA2MTI1MA==&amp;mid=2649093605&amp;idx=3&amp;sn=d33708df74ef6ff2b2b466cacc39f910&amp;chksm=be5bd248892c5b5ef9132825d3cfc8f409691ac5926a25d1d17e9acf198942d7dc805ad24e65&amp;scene=21#wechat_redirect\">\u3010JavaScript \u6559\u7a0b\u3011\u6d4f\u89c8\u5668\u2014window \u5bf9\u8c61<\/a><\/section>\n<\/li>\n<li>\n<section><a href=\"http:\/\/mp.weixin.qq.com\/s?__biz=MjM5MDA2MTI1MA==&amp;mid=2649093583&amp;idx=3&amp;sn=2c7418baffa86a68bbbf8be0666ebcf9&amp;chksm=be5bd262892c5b74cceb3082cc881ed13c539c1c09705e76c5673c59a2dda67cb719cebf24d4&amp;scene=21#wechat_redirect\">\u3010JavaScript \u6559\u7a0b\u3011\u6d4f\u89c8\u5668\u2014\u6d4f\u89c8\u5668\u73af\u5883\u6982\u8ff0<\/a><\/section>\n<\/li>\n<li>\n<section><a href=\"http:\/\/mp.weixin.qq.com\/s?__biz=MjM5MDA2MTI1MA==&amp;mid=2649093700&amp;idx=3&amp;sn=985e857531714a3496bdf7248efdb524&amp;chksm=be5bd1e9892c58ff8ee0d77678b68f476db0d54eebd77897bf1d5c6bd5decf65410241673fc1&amp;scene=21#wechat_redirect\">XMLHttpRequest \u5bf9\u8c61<\/a><\/section>\n<\/li>\n<li>\n<section><a href=\"http:\/\/mp.weixin.qq.com\/s?__biz=MjM5MDA2MTI1MA==&amp;mid=2649093808&amp;idx=4&amp;sn=d28aca49deb6006fa436f06eaa00242e&amp;chksm=be5bd11d892c580b3b79b8baf388251229258e533dc0950f0a302d75388707ebd322b489ee04&amp;scene=21#wechat_redirect\">\u3010JavaScript \u6559\u7a0b\u3011\u6d4f\u89c8\u5668\u2014\u540c\u6e90\u9650\u5236<\/a><\/section>\n<\/li>\n<li>\n<section><a href=\"http:\/\/mp.weixin.qq.com\/s?__biz=MjM5MDA2MTI1MA==&amp;mid=2649093824&amp;idx=4&amp;sn=b082d0b84b1f5fc3a92a61519e7f709a&amp;chksm=be5bd16d892c587bbdca83d4194194149c40d6f3ff56cb53ac79c87515b12aec2bb377738724&amp;scene=21#wechat_redirect\">\u3010JavaScript \u6559\u7a0b\u3011\u6d4f\u89c8\u5668\u2014CORS \u901a\u4fe1<\/a><\/section>\n<\/li>\n<li>\n<section><a href=\"http:\/\/mp.weixin.qq.com\/s?__biz=MjM5MDA2MTI1MA==&amp;mid=2649093844&amp;idx=3&amp;sn=52664f94e9f1a9cb9b7350a90bf800cf&amp;chksm=be5bd179892c586fb5c65782fcc819be3e27b2317db7e2a9c0aca7942672116ecc5674f09ba8&amp;scene=21#wechat_redirect\">\u3010JavaScript \u6559\u7a0b\u3011\u6d4f\u89c8\u5668\u2014Storage \u63a5\u53e3<\/a><\/section>\n<\/li>\n<li>\n<section><a href=\"http:\/\/mp.weixin.qq.com\/s?__biz=MjM5MDA2MTI1MA==&amp;mid=2649093921&amp;idx=3&amp;sn=6a6d0ea19a93a3d84411e322a62e9b06&amp;chksm=be5bd08c892c599a1a677afe1071f1b3ee53caec4bfc7da4541fd4c5c32c3726c74ad33532d1&amp;scene=21#wechat_redirect\">\u3010JavaScript \u6559\u7a0b\u3011\u6d4f\u89c8\u5668\u2014History \u5bf9\u8c61<\/a><\/section>\n<\/li>\n<li>\n<section><a href=\"http:\/\/mp.weixin.qq.com\/s?__biz=MjM5MDA2MTI1MA==&amp;mid=2649093966&amp;idx=3&amp;sn=9d8440c8233cf70a64ec3409bb6fa5cb&amp;chksm=be5bd0e3892c59f5baa64df6e7f58181dbf066cc20d877856bcced1d8387cae0f4c1f7f72bf4&amp;scene=21#wechat_redirect\">Location\u5bf9\u8c61\uff0cURL\u5bf9\u8c61\uff0cURLSearchParams;\u5bf9\u8c61<\/a><\/section>\n<\/li>\n<li>\n<section><a href=\"http:\/\/mp.weixin.qq.com\/s?__biz=MjM5MDA2MTI1MA==&amp;mid=2649094033&amp;idx=3&amp;sn=43601627bae912056159667af9e6b263&amp;chksm=be5bd03c892c592a4bd894f25b4ed5af0c91a50a418d549e4318bf649193a8d2a4ba37c93c5b&amp;scene=21#wechat_redirect\">\u3010JavaScript \u6559\u7a0b\u3011\u6d4f\u89c8\u5668\u2014ArrayBuffer\u5bf9\u8c61\uff0cBlob\u5bf9\u8c61<\/a><\/section>\n<\/li>\n<\/ul>\n<blockquote style=\"display: block; font-size: 0.9em; border-left: 3px solid #4870ac; padding: 0.5em 1em; margin: 0px; background: #f6f8fa; color: #40464f;\">\n<p style=\"margin: 1em 0px;\"><strong style=\"color: #4870ac;\">\u4e00\u53e5\u8bdd\u603b\u7ed3\uff1a\u9009\u6587\u4ef6\u5f97\u5230 FileList\uff0c\u6210\u5458\u662f File\uff08Blob \u7684\u5b50\u7c7b\uff09\uff1b\u8981\u7528\u5185\u5bb9\u5c31 new FileReader\uff0c\u6309\u6587\u672c\u3001\u4e8c\u8fdb\u5236\u6216 Data URL \u4e09\u79cd\u683c\u5f0f\u8bfb\u3002<\/strong><\/p>\n<\/blockquote>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>\u6d4f\u89c8\u5668\u91cc\u8bfb\u5199\u672c\u5730\u6587\u4ef6\uff0c\u5e38\u7528\u4e09\u4e2a\u5bf9\u8c61\uff1aFile\u3001FileList\u3001FileReader\u3002File \u7ee7\u627f Blob [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[109,105],"tags":[150],"_links":{"self":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/3043"}],"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=3043"}],"version-history":[{"count":1,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/3043\/revisions"}],"predecessor-version":[{"id":3044,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/3043\/revisions\/3044"}],"wp:attachment":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3043"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3043"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3043"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}