{"id":158337,"date":"2024-05-08T12:48:42","date_gmt":"2024-05-08T04:48:42","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/158337.html"},"modified":"2024-05-08T12:48:48","modified_gmt":"2024-05-08T04:48:48","slug":"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8-javascript-%e5%b0%86%e6%9c%ac%e5%9c%b0%e5%9b%be%e7%89%87%e8%bd%ac%e6%8d%a2%e4%b8%ba%e4%ba%8c%e8%bf%9b%e5%88%b6%e6%95%b0%e6%8d%ae","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/158337.html","title":{"rendered":"\u5982\u4f55\u4f7f\u7528 JavaScript \u5c06\u672c\u5730\u56fe\u7247\u8f6c\u6362\u4e3a\u4e8c\u8fdb\u5236\u6570\u636e"},"content":{"rendered":"<p style=\"text-align:center\"><img decoding=\"async\" src=\"https:\/\/cdn-kb.worktile.com\/kb\/wp-content\/uploads\/2024\/04\/26220842\/1d66186a-7535-4157-888d-9c3bf9cdd8cd.webp\" alt=\"\u5982\u4f55\u4f7f\u7528 JavaScript \u5c06\u672c\u5730\u56fe\u7247\u8f6c\u6362\u4e3a\u4e8c\u8fdb\u5236\u6570\u636e\" \/><\/p>\n<p><p>\u4f7f\u7528JavaScript\u5c06\u672c\u5730\u56fe\u7247\u8f6c\u6362\u4e3a\u4e8c\u8fdb\u5236\u6570\u636e\u901a\u5e38\u662f\u4e3a\u4e86\u65b9\u4fbf\u56fe\u7247\u4e0a\u4f20\u3001\u524d\u7aef\u56fe\u7247\u5904\u7406\u6216\u8005\u5728\u5ba2\u6237\u7aef\u8fdb\u884c\u56fe\u7247\u5206\u6790\u7b49\u64cd\u4f5c\u3002<strong>\u4e3b\u8981\u65b9\u6cd5\u5305\u62ec\uff1a\u4f7f\u7528 FileReader API\u3001\u4f7f\u7528 Canvas \u4ee5\u53ca\u5229\u7528 XMLHttpRequest (\u6216 Fetch API)<\/strong>\u3002\u8fd9\u91cc\uff0c\u6211\u4eec\u4f1a\u8be6\u7ec6\u63a2\u8ba8\u4f7f\u7528 FileReader API \u7684\u65b9\u5f0f\uff0c\u5b83\u63d0\u4f9b\u4e86\u4e00\u4e2a\u7b80\u5355\u7684\u65b9\u6cd5\u6765\u8bfb\u53d6\u6587\u4ef6\u5185\u5bb9\uff0c\u5e76\u53ef\u4ee5\u5c06\u6587\u4ef6\u5185\u5bb9\u8bfb\u53d6\u4e3a\u4e8c\u8fdb\u5236\u6570\u636e\uff0c\u65b9\u4fbf\u540e\u7eed\u5904\u7406\u3002<\/p>\n<\/p>\n<p><p><strong>FileReader API<\/strong> \u662f Web API \u7684\u4e00\u90e8\u5206\uff0c\u5b83\u5141\u8bb8web\u5e94\u7528\u7a0b\u5e8f\u5f02\u6b65\u8bfb\u53d6\u5b58\u50a8\u5728\u7528\u6237\u8ba1\u7b97\u673a\u4e0a\u7684\u6587\u4ef6\uff08\u5305\u62ecBufferArray\u3001\u6587\u672c\u3001\u4e8c\u8fdb\u5236\u6570\u636e\u7b49\uff09\uff0c\u4f7f\u7528 <code>readAsArrayBuffer<\/code> \u65b9\u6cd5\u53ef\u4ee5\u5c06\u56fe\u7247\u6587\u4ef6\u8bfb\u53d6\u4e3aArrayBuffer\u5bf9\u8c61\uff0c\u5176\u4e2d\u50a8\u5b58\u7740\u56fe\u7247\u7684\u4e8c\u8fdb\u5236\u6570\u636e\uff0c\u63a5\u4e0b\u6765\u53ef\u4ee5\u5c06\u8fd9\u4e2a\u4e8c\u8fdb\u5236\u6570\u636e\u901a\u8fc7\u4e0d\u540c\u7684\u65b9\u5f0f\u8fdb\u884c\u5904\u7406\u548c\u4f7f\u7528\u3002<\/p>\n<\/p>\n<p><p>\u4e00\u3001\u4f7f\u7528FILEREADER API\u5c06\u56fe\u7247\u8f6c\u6362\u4e3a\u4e8c\u8fdb\u5236\u6570\u636e<\/p>\n<\/p>\n<p><p>\u9996\u5148\uff0c\u4f60\u9700\u8981\u83b7\u53d6\u5230\u7528\u6237\u9009\u53d6\u7684\u672c\u5730\u56fe\u7247\uff0c\u8fd9\u53ef\u4ee5\u901a\u8fc7\u4e00\u4e2a\u6587\u4ef6\u8f93\u5165\uff08<code>&lt;input type=&quot;file&quot;&gt;<\/code>\uff09\u63a7\u4ef6\u5b8c\u6210\u3002\u5f53\u7528\u6237\u9009\u62e9\u6587\u4ef6\u540e\uff0c\u53ef\u4ee5\u4f9d\u8d56 <code>FileReader<\/code> \u5bf9\u8c61\u548c\u5176 <code>readAsArrayBuffer<\/code> \u65b9\u6cd5\u6765\u8f6c\u6362\u8fd9\u4e2a\u56fe\u7247\u6587\u4ef6\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-javascript\">\/\/ HTML \u90e8\u5206<\/p>\n<p>&lt;input type=&quot;file&quot; id=&quot;image-input&quot; accept=&quot;image\/*&quot;&gt;<\/p>\n<p>\/\/ JavaScript \u90e8\u5206<\/p>\n<p>document.getElementById(&#039;image-input&#039;).addEventListener(&#039;change&#039;, function(e) {<\/p>\n<p>  const file = e.target.files[0];<\/p>\n<p>  if (file) {<\/p>\n<p>    const reader = new FileReader();<\/p>\n<p>    reader.onload = function(event) {<\/p>\n<p>      const arrayBuffer = event.target.result;<\/p>\n<p>      \/\/ \u6b64\u65f6\u7684 arrayBuffer \u5373\u4e3a\u56fe\u7247\u7684\u4e8c\u8fdb\u5236\u6570\u636e<\/p>\n<p>    };<\/p>\n<p>    reader.readAsArrayBuffer(file);<\/p>\n<p>  }<\/p>\n<p>});<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><p>\u901a\u8fc7\u4e0a\u8ff0\u4ee3\u7801\uff0c\u5f53\u7528\u6237\u9009\u62e9\u4e86\u56fe\u7247\u6587\u4ef6\u540e\uff0c<code>FileReader<\/code> \u5b9e\u4f8b\u5f00\u59cb\u8bfb\u53d6\u6587\u4ef6\u5e76\u89e6\u53d1 <code>onload<\/code> \u4e8b\u4ef6\uff0c\u6b64\u65f6\u7684 <code>event.target.result<\/code> \u5305\u542b\u4e86\u56fe\u7247\u7684\u4e8c\u8fdb\u5236\u6570\u636e\u3002<\/p>\n<\/p>\n<p><p>\u4e8c\u3001\u5904\u7406OBT<a href=\"https:\/\/docs.pingcode.com\/blog\/59162.html\" target=\"_blank\">AI<\/a>NED 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file.name);<\/p>\n<p>fetch(&#039;upload-endpoint&#039;, {<\/p>\n<p>  method: &#039;POST&#039;,<\/p>\n<p>  body: formData<\/p>\n<p>})<\/p>\n<p>.then(response =&gt; response.json())<\/p>\n<p>.then(result =&gt; {<\/p>\n<p>  console.log(&#039;Success:&#039;, result);<\/p>\n<p>})<\/p>\n<p>.catch(error =&gt; {<\/p>\n<p>  console.error(&#039;Error:&#039;, error);<\/p>\n<p>});<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><p>\u4e09\u3001\u4f7f\u7528 CANVAS \u8f6c\u6362\u56fe\u7247<\/p>\n<\/p>\n<p><p>\u53e6\u5916\u4e00\u79cd\u65b9\u5f0f\u662f\u4f7f\u7528 HTML5 Canvas API\u3002\u9996\u5148\u5728\u753b\u5e03\u4e0a\u7ed8\u5236\u56fe\u50cf\uff0c\u7136\u540e\u53ef\u4ee5\u901a\u8fc7Canvas\u63d0\u4f9b\u7684API\u6765\u63d0\u53d6\u4e8c\u8fdb\u5236\u6570\u636e\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-javascript\">\/\/ HTML\u90e8\u5206<\/p>\n<p>&lt;canvas id=&quot;canvas&quot;&gt;&lt;\/canvas&gt;<\/p>\n<p>\/\/ JavaScript\u90e8\u5206<\/p>\n<p>document.getElementById(&#039;image-input&#039;).addEventListener(&#039;change&#039;, function(e) {<\/p>\n<p>  const file = e.target.files[0];<\/p>\n<p>  if (file) {<\/p>\n<p>    const img = new Image();<\/p>\n<p>    const canvas = document.getElementById(&#039;canvas&#039;);<\/p>\n<p>    const ctx = canvas.getContext(&#039;2d&#039;);<\/p>\n<p>    img.onload = function() {<\/p>\n<p>      canvas.width = img.width;<\/p>\n<p>      canvas.height = img.height;<\/p>\n<p>      ctx.drawImage(img, 0, 0);<\/p>\n<p>      canvas.toBlob(function(blob) {<\/p>\n<p>        \/\/ \u6b64\u65f6\u7684blob\u5c31\u662f\u8f6c\u6362\u540e\u7684\u4e8c\u8fdb\u5236\u5f62\u5f0f\u7684\u56fe\u50cf\u6570\u636e<\/p>\n<p>      }, file.type);<\/p>\n<p>    };<\/p>\n<p>    img.src = URL.createObjectURL(file);<\/p>\n<p>  }<\/p>\n<p>});<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><p>\u56db\u3001\u4f7f\u7528 XMLHttpRequest \u6216 FETCH API<\/p>\n<\/p>\n<p><p>\u5728\u73b0\u4ee3\u6d4f\u89c8\u5668\u4e2d\uff0c<code>Fetch API<\/code> \u63d0\u4f9b\u4e86\u4e00\u79cd\u7b80\u6d01\u6e05\u6670\u7684\u65b9\u5f0f\u6765\u8fdb\u884c\u7f51\u7edc\u8bf7\u6c42\uff0c\u5305\u62ec\u4e0a\u4f20\u6587\u4ef6\u3002<\/p>\n<\/p>\n<p><p>\u5982\u679c\u4f60\u60f3\u4f7f\u7528\u66f4\u5e95\u5c42\u7684 <code>XMLHttpRequest()<\/code> \u6765\u5904\u7406\u6587\u4ef6\u4e0a\u4f20\uff0c\u90a3\u4e48\u4f60\u9700\u8981\u521b\u5efa\u4e00\u4e2a <code>FormData<\/code> \u5bf9\u8c61\u5e76\u901a\u8fc7 <code>append()<\/code> \u65b9\u6cd5\u6dfb\u52a0\u6587\u4ef6\u3002\u7136\u800c\uff0c\u8981\u6ce8\u610f\u7684\u662f\uff0c\u4ece\u6587\u4ef6\u5bf9\u8c61\u76f4\u63a5\u8bfb\u53d6\u5f97\u5230\u7684\u4e8c\u8fdb\u5236\u6570\u636e\u662f\u4e0d\u53ef\u4ee5\u76f4\u63a5\u9644\u52a0\u5230 <code>FormData<\/code> \u5bf9\u8c61\u7684\uff0c\u9700\u8981\u5c06\u5176\u8f6c\u6362\u4e3a <code>Blob<\/code> \u5bf9\u8c61\u3002<\/p>\n<\/p>\n<p><p>\u4f7f\u7528\u4e8c\u8fdb\u5236\u6570\u636e\u7684\u76ee\u7684\u5404\u5f02\uff0c\u6211\u4eec\u5728\u8fd9\u91cc\u5df2\u7ecf\u4ecb\u7ecd\u4e86\u5c06\u672c\u5730\u56fe\u7247\u8f6c\u6362\u4e3a\u4e8c\u8fdb\u5236\u6570\u636e\u7684\u4e3b\u8981\u65b9\u6cd5\u53ca\u5176\u90e8\u5206\u5e94\u7528\u3002\u65e0\u8bba\u60a8\u662f\u9700\u8981\u5c06\u56fe\u7247\u76f4\u63a5\u4ee5\u4e8c\u8fdb\u5236\u5f62\u5f0f\u50a8\u5b58\u3001\u63d0\u524d\u5728\u5ba2\u6237\u7aef\u8fdb\u884c\u56fe\u7247\u89e3\u6790\u8fd8\u662f\u4e0a\u4f20\u5230\u8fdc\u7aef\u670d\u52a1\u5668\uff0c\u4e0a\u8ff0\u4ecb\u7ecd\u7684\u65b9\u6cd5\u90fd\u662f\u5341\u5206\u6709\u7528\u7684\u5de5\u5177\u3002<\/p>\n<\/p>\n<h2><strong>\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n<p><strong>\u95ee\u98981\uff1a\u5982\u4f55\u4f7f\u7528 JavaScript \u5c06\u672c\u5730\u56fe\u7247\u8f6c\u6362\u4e3a\u4e8c\u8fdb\u5236\u6570\u636e\uff1f<\/strong><\/p>\n<p>\u56de\u7b541\uff1a\u8981\u5c06\u672c\u5730\u56fe\u7247\u8f6c\u6362\u4e3a\u4e8c\u8fdb\u5236\u6570\u636e\uff0c\u53ef\u4ee5\u4f7f\u7528FileReader\u5bf9\u8c61\u548cCanvas\u5143\u7d20\u6765\u5b9e\u73b0\u3002\u9996\u5148\uff0c\u4f7f\u7528input\u5143\u7d20\u9009\u62e9\u8981\u4e0a\u4f20\u7684\u672c\u5730\u56fe\u7247\u6587\u4ef6\u3002\u7136\u540e\uff0c\u901a\u8fc7FileReader\u5bf9\u8c61\u8bfb\u53d6\u8be5\u6587\u4ef6\uff0c\u5e76\u5c06\u5176\u8f6c\u6362\u4e3aData URL\u683c\u5f0f\u7684\u5b57\u7b26\u4e32\u3002\u63a5\u4e0b\u6765\uff0c\u521b\u5efa\u4e00\u4e2aImage\u5bf9\u8c61\uff0c\u5c06Data 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