在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

readAsBinaryString method is used to start reading the contents of the specified Blob or File . When the read operation is finished, the readyState becomes DONE ，和 loadend is triggered. At that time, the result attribute contains the raw binary data from the file.

Note that this method was once removed from the File API specification, but re-introduced for backward compatibility.
使用 FileReader.readAsArrayBuffer() is recommended.

句法

instanceOfFileReader.readAsBinaryString(blob);
					

参数

blob

Blob or File from which to read.

范例

var canvas = document.createElement('canvas');
var height = 200;
var width  = 200;
canvas.width  = width;
canvas.height = height;
var ctx = canvas.getContext('2d');
ctx.strokeStyle = '#090';
ctx.beginPath();
ctx.arc(width/2, height/2, width/2 - width/10, 0, Math.PI*2);
ctx.stroke();
canvas.toBlob(function (blob) {
  var reader = new FileReader();
  reader.onload = function () {
    console.log(reader.result);
  }
  reader.readAsBinaryString(blob);
});
					

规范

规范	状态	注释
文件 API The definition of 'readAsBinaryString' in that specification.	工作草案

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
readAsBinaryString	Chrome 7	Edge 12	Firefox 3.6	IE No	Opera 11	Safari 6	WebView Android ≤37	Chrome Android 18	Firefox Android 32	Opera Android 11	Safari iOS 6.1	Samsung Internet Android 1.0

图例

完整支持

完整支持

不支持

不支持

另请参阅

• FileReader

元数据

• 最后修改： 2019 年 3 月 23 日

相关话题

1. FileReader
2. 构造函数

   1. FileReader()
3. 特性

   1. error
   2. onabort
   3. onload
   4. readyState
   5. result
4. 方法

   1. abort()
   2. readAsArrayBuffer()
   3. readAsBinaryString()
   4. readAsDataURL()
   5. readAsText()
5. 事件

   1. abort
   2. error
   3. load
   4. loadend
   5. loadstart
   6. progress
6. 继承：

   1. EventTarget
7. 文件 API 相关页面

   1. Blob
   2. File
   3. FileList
   4. FileReaderSync