FileReader:readyState 属性

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since January 2020.

备注: 此特性在 Web Worker 中可用。

FileReader 接口的 readyState 只读属性提供读取操作的当前状态。这将是以下状态之一:EMPTYLOADINGDONE

一个数字,它是 FileReader 接口上定义的三个可能的状态常量之一:

FileReader.EMPTY(0)

Reader 已创建,但尚未调用任何读取方法。

FileReader.LOADING(1)

已调用读取方法。正在读取 FileBlob,尚未发生错误。

FileReader.DONE(2)

读取操作完成。这可能意味着:整个 FileBlob 已读入内存,发生文件读取错误,或 abort() 被调用并且读取被取消。

示例

js
const reader = new FileReader();
console.log("EMPTY", reader.readyState); // readyState 将为 0
reader.readAsText(blob);
console.log("LOADING", reader.readyState); // readyState 将为 1
reader.onloadend = () => {
  console.log("DONE", reader.readyState); // readyState 将为 2
};

规范

Specification
File API
# dom-filereader-readystate

浏览器兼容性

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
readyState

Legend

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Full support
Full support

参见