设置@grant值时，如何访问“窗口”（目标页面）对象？

当您设置任何

@grant

现在，为了在目标页面范围内创建或覆盖变量，您必须从技术菜单中正确选择。例如：

To Read:

• 一个简单的变量：

  Target page sets:       var foo = "bar";

  GM script can read: unsafeWindow.foo //– “bar”

• 一个简单的对象：

  Target page sets:       var obj = {A: 1};

  GM script can read: unsafeWindow.obj //– Object { A: 1 }

• 一个复杂的对象： 这并不总是可能的。

To Call:

• 一个简单的功能：

  Target page sets:       function func () {console.log ('Hi');}

  GM script can call: unsafeWindow.func() //– “Hi”

To Write/Set:

• 一个简单的变量：

  unsafeWindow.foo = "Apple";

• 一个简单的对象：

  var gmObject        = {X: "123"};

  unsafeWindow.obj = cloneInto (gmObject, unsafeWindow);

• 一个简单的功能：

  function gmFunc () {console.log ("Lorem ipsum");//-- Can use GM_ functions in here! :)

  }
  unsafeWindow.func = exportFunction (gmFunc, unsafeWindow);
  

考虑以下HTML：

<button id="helloBtn">Say "Hello".</button>

而这个Javascript：

var simpleGlobalVar = "A simple, global var in the page scope.";var globalObject    = {Letter: "A", Number: 2};function simpleFunction () {    console.log ("The target page's simpleFunction was called.");}var sayHello = function() {    console.log ('Hello.');}document.getElementById ('helloBtn').addEventListener ('click', function () {    sayHello ();} );

如果在该页面上安装并运行此Greasemonkey脚本：

// ==Userscript==// @name     _Demonstrate accessing target-page variables with @grant values set// @include  http://fiddle.jshell.net/sepwL7n6/*/show/// @require  http://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js// @grant    GM_addStyle// ==/Userscript==console.log ("*** Greasemonkey script start.");$("body").append ('<div id="gmArea">Added by Greasemonkey:<p></p></div>');$("#gmArea > p:first").append ('<button id="gmShow">Access select target-page variables and functions</button>');$("#gmArea > p:first").append ('<button id="gmChange">Change javascript things in the target-page scope.</button>');$("#gmShow").click ( function () {    //-- Access things from the target-page scope:    console.log ("----------------");    console.log ("==> simpleGlobalVar is: ", unsafeWindow.simpleGlobalVar);    console.log ("==> globalObject    is: ", unsafeWindow.globalObject);    console.log ("==> Calling target's simpleFunction():");    unsafeWindow.simpleFunction ();    //-- WARNING! This next technique is not robust, but works in some cases.    console.log ("==> Calling target's button's click().");    unsafeWindow.document.getElementById ('helloBtn').click ();} );$("#gmChange").click ( function () {    this.disabled = true;   //-- Can only click once.    unsafeWindow.simpleGlobalVar    = "Simple var... Intercepted by GM!";    unsafeWindow.globalObject       = cloneInto (gmObject, unsafeWindow);    unsafeWindow.sayHello= exportFunction (sayHello, unsafeWindow);    console.log ("==> Target page objects were changed.");} );var gmMessageStr    = "Function... Intercepted by GM, but also can use GM_ functions!";function sayHello () {    sayHello.K      = (sayHello.K  ||  0) + 1;    console.log (gmMessageStr);    GM_addStyle ('body {background: ' + (sayHello.K % 2  ?  "lime"  :  "white") + ';}');}var gmObject        = {message: "Object overridden by GM."};

打开控制台并按下按钮，您将看到GM脚本能够读取和更改页面的变量和功能。

笔记：

1. 这是所有 特定于Firefox的 。
2. 对于跨平台代码和某些复杂情况，可以改用脚本注入 。但是注入的代码不能直接访问

   GM_

   函数。
3. 请注意，这些技术仅适用于全局的javascript变量和函数。