webFrame

自定义渲染当前网页

进程: Renderer

webFrame export of the Electron module is an instance of the WebFrame class representing the top frame of the current BrowserWindow. Sub-frames can be retrieved by certain properties and methods (e.g. webFrame.firstChild).

将当前页缩放到200% 的示例。

const { webFrame } = require('electron')
webFrame.setZoomFactor(2)

方法

The WebFrame class has the following instance methods:

webFrame.setZoomFactor(factor)

• factor Double - Zoom factor; default is 1.0.

Changes the zoom factor to the specified factor. Zoom factor is zoom percent divided by 100, so 300% = 3.0.

The factor must be greater than 0.0.

webFrame.getZoomFactor()

Returns Number - 当前的缩放比例。

webFrame.setZoomLevel(level)

• level Number - 缩放等级。

更改缩放等级。 The original size is 0 and each increment above or below represents zooming 20% larger or smaller to default limits of 300% and 50% of original size, respectively.

webFrame.getZoomLevel()

Returns Number - The current zoom level.

webFrame.setVisualZoomLevelLimits(minimumLevel, maximumLevel)

• minimumLevel Number
• maximumLevel Number

设置最大和最小缩放级别。

NOTE: Visual zoom is disabled by default in Electron. To re-enable it, call:

js webFrame.setVisualZoomLevelLimits(1, 3)

webFrame.setLayoutZoomLevelLimits(minimumLevel, maximumLevel) Deprecated

• minimumLevel Number
• maximumLevel Number

设置最大和最小基于布局(例如非图像)的缩放级别。

Deprecated: This API is no longer supported by Chromium.

webFrame.setSpellCheckProvider(language, provider)

• language String
• provider Object
  • spellCheck Function
    • words String[]
    • callback Function
      • misspeltWords String[]

Sets a provider for spell checking in input fields and text areas.

If you want to use this method you must disable the builtin spellchecker when you construct the window.

const mainWindow = new BrowserWindow({
  webPreferences: {
    spellcheck: false
  }
})

The provider must be an object that has a spellCheck method that accepts an array of individual words for spellchecking. The spellCheck function runs asynchronously and calls the callback function with an array of misspelt words when complete.

An example of using node-spellchecker as provider:

const { webFrame } = require('electron')
const spellChecker = require('spellchecker')
webFrame.setSpellCheckProvider('en-US', {
  spellCheck (words, callback) {
    setTimeout(() => {
      const spellchecker = require('spellchecker')
      const misspelled = words.filter(x => spellchecker.isMisspelled(x))
      callback(misspelled)
    }, 0)
  }
})

webFrame.insertCSS(css)

• css String - CSS source code.

Returns String - A key for the inserted CSS that can later be used to remove the CSS via webFrame.removeInsertedCSS(key).

Injects CSS into the current web page and returns a unique key for the inserted stylesheet.

webFrame.removeInsertedCSS(key)

• key String

Removes the inserted CSS from the current web page. The stylesheet is identified by its key, which is returned from webFrame.insertCSS(css).

webFrame.insertText(text)

• text String

插入text 到焦点元素

webFrame.executeJavaScript(code[, userGesture])

• code String
• userGesture Boolean (optional) - Default is false.

Returns Promise<any> - A promise that resolves with the result of the executed code or is rejected if the result of the code is a rejected promise.

在页面中执行 code。

在浏览器窗口中，一些HTML API（如requestFullScreen）只能是 由来自用户的手势调用。 将 userGesture 设置为 true 将删除此限制。

webFrame.executeJavaScriptInIsolatedWorld(worldId, scripts[, userGesture])

• worldId Integer - The ID of the world to run the javascript in, 0 is the default world, 999 is the world used by Electrons contextIsolation feature. You can provide any integer here.
• scripts WebSource[]
• userGesture Boolean (optional) - Default is false.

Returns Promise<any> - A promise that resolves with the result of the executed code or is rejected if the result of the code is a rejected promise.

Works like executeJavaScript but evaluates scripts in an isolated context.

webFrame.setIsolatedWorldInfo(worldId, info)

• worldId Integer - The ID of the world to run the javascript in, 0 is the default world, 999 is the world used by Electrons contextIsolation feature. Chrome extensions reserve the range of IDs in [1 << 20, 1 << 29). You can provide any integer here.
• info Object
  • securityOrigin String (optional) - Security origin for the isolated world.
  • csp String (optional) - Content Security Policy for the isolated world.
  • name String (optional) - Name for isolated world. Useful in devtools.

Set the security origin, content security policy and name of the isolated world. Note: If the csp is specified, then the securityOrigin also has to be specified.

webFrame.getResourceUsage()

返回 Object:

• images MemoryUsageDetails
• scripts MemoryUsageDetails
• cssStyleSheets MemoryUsageDetails
• xslStyleSheets MemoryUsageDetails
• fonts MemoryUsageDetails
• other MemoryUsageDetails

Returns an object describing usage information of Blink’s internal memory caches.

const { webFrame } = require('electron')
console.log(webFrame.getResourceUsage())

This will generate:

{
  images: {
    count: 22,
    size: 2549,
    liveSize: 2542
  },
  cssStyleSheets: { /* same with "images" */ },
  xslStyleSheets: { /* same with "images" */ },
  fonts: { /* same with "images" */ },
  other: { /* same with "images" */ }
}

webFrame.clearCache()

尝试释放不再使用的内存 (如以前导航中的图像)。

请注意, 盲目调用此方法可能使Electron较慢, 因为它将不得不重新填充这些清空的缓存。你应该只在这种情况下调用它, 就是当你的应用程序发生的一个事件, 使你认为你的网页实际只使用了较少的内存 (例如你从一个超级重页跳转到一个基本为空的页面, 并打算留在那)。

webFrame.getFrameForSelector(selector)

• selector String - CSS selector for a frame element.

Returns WebFrame - The frame element in webFrame's document selected by selector, null would be returned if selector does not select a frame or if the frame is not in the current renderer process.

webFrame.findFrameByName(name)

• name 字符串

Returns WebFrame - A child of webFrame with the supplied name, null would be returned if there’s no such frame or if the frame is not in the current renderer process.

webFrame.findFrameByRoutingId(routingId)

• routingId Integer - An Integer representing the unique frame id in the current renderer process. Routing IDs can be retrieved from WebFrame instances (webFrame.routingId) and are also passed by frame specific WebContents navigation events (e.g. did-frame-navigate)

Returns WebFrame - that has the supplied routingId, null if not found.

属性

webFrame.top Readonly

A WebFrame | null representing top frame in frame hierarchy to which webFrame belongs, the property would be null if top frame is not in the current renderer process.

webFrame.opener Readonly

A WebFrame | null representing the frame which opened webFrame, the property would be null if there’s no opener or opener is not in the current renderer process.

webFrame.parent Readonly

A WebFrame | null representing parent frame of webFrame, the property would be null if webFrame is top or parent is not in the current renderer process.

webFrame.firstChild Readonly

A WebFrame | null representing the first child frame of webFrame, the property would be null if webFrame has no children or if first child is not in the current renderer process.

webFrame.nextSibling Readonly

A WebFrame | null representing next sibling frame, the property would be null if webFrame is the last frame in its parent or if the next sibling is not in the current renderer process.

webFrame.routingId Readonly

An Integer representing the unique frame id in the current renderer process. Distinct WebFrame instances that refer to the same underlying frame will have the same routingId.