在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

过时
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.

HTMLCanvasElement.mozFetchAsStream() internal method used to create a new input stream that, when ready, would provide the contents of the canvas as image data. However, this non-standard and internal method has been removed.

句法

void canvas.mozFetchAsStream(callback, type);
					

参数

callback

An nsIInputStreamCallback .

type 可选

DOMString indicating the image format. The default type is image/png .

返回值

None.

范例

Save to disk with mozFetchAsStream (Chrome context only)

This technique also converts it to ico, however it will not work in Windows XP as WinXP cannot convert from PNG to ICO. It saves to the desktop it uses FileUtils.jsm. Also uses NetUtil.jsm

var canvas = document.getElementById('canvas');
var d = canvas.width;
ctx = canvas.getContext('2d');
ctx.beginPath();
ctx.moveTo(d / 2, 0);
ctx.lineTo(d, d);
ctx.lineTo(0, d);
ctx.closePath();
ctx.fillStyle = 'yellow';
ctx.fill();
var netutilCallback = function() {
    return function(result) {
       if (!Components.isSuccessCode(result)) {
          alert('FAILED to create icon');
       } else {
           alert('succesfully made');
       }
    };
}
var mfasCallback = function(iconName) {
    return function(inStream) {
       var file = FileUtils.getFile('Desk', [iconName + '.ico']);
       var outStream = FileUtils.openFileOutputStream(file);
       Cu.import('resource://gre/modules/NetUtil.jsm');
       NetUtil.asyncCopy(inStream, outStream, netutilCallback());
    }
}
canvas.mozFetchAsStream(mfasCallback('myIcon'), 'image/vnd.microsoft.icon');
					

规范

Not part of any specification.

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
mozFetchAsStream 弃用 非标	Chrome No	Edge No	Firefox 13 — 43	IE No	Opera No	Safari No	WebView Android No	Chrome Android No	Firefox Android No	Opera Android No	Safari iOS No	Samsung Internet Android No

图例

不支持

不支持

非标。预期跨浏览器支持较差。

非标。预期跨浏览器支持较差。

弃用。不要用于新网站。

弃用。不要用于新网站。

另请参阅

• The interface defining it, HTMLCanvasElement .

元数据

• 最后修改： 2019 年 3 月 23 日

相关话题

1. 画布 API
2. HTMLCanvasElement
3. 特性

   1. height
   2. mozOpaque
   3. width
4. 方法

   1. captureStream()
   2. getContext()
   3. mozFetchAsStream()
   4. mozGetAsFile()
   5. toBlob()
   6. toDataURL()
   7. transferControlToOffscreen()
5. 事件

   1. webglcontextlost
6. 继承：

   1. HTMLElement
   2. 元素
   3. 节点
   4. EventTarget
7. Related pages for Canvas API

   1. Canvas
   2. CanvasGradient
   3. CanvasImageSource
   4. CanvasPattern
   5. CanvasRenderingContext2D
   6. ImageBitmap
   7. ImageBitmapFactories
   8. ImageBitmapRenderingContext
   9. ImageData
   10. OffscreenCanvas
   11. Path2D
   12. RenderingContext
   13. TextMetrics