angularjs – 从Angular表达式访问窗口

Unlike JavaScript,where names default to global window properties,Angular expressions have to use $window to refer to the global window object. For example,if you want to call alert(),which is defined on window,in an expression you must use $window.alert().

但是我似乎无法从使用$scope评估的表达式访问$window.$eval.
以下是我在登录控制台时获得的一些输出：

console.log($window);                   // the Window object as expected
console.log($scope.$eval('$window'));   // undefined
console.log($scope.$eval('1+1'));       // 2
console.log($scope.$eval('scopeVar'));  // 'abc'

控制器将$window作为依赖项.我可以从表达式而不是$window访问范围变量和其他服务,因此$scope.$eval($window.alert())也不起作用.

我在这里错过了什么？