angularjs - 检查元素是否已经有监听器

Question

如何检查特定事件监听器是否已绑定(bind)到元素？例如:

myApp.directive("myDirective", function ($document) {
    return {
        restrict: "A",
        scope: {},
        link: function (scope, elem, attrs) {
            var myListener = function () {
                alert("Hello!!!");
            };
            elem.on("click", function () {
                if (!$document.hasEvent("click", myListener)) { // Check in here
                    $document.on("click", myListener);
                }
            });
        }
    }
});

hasEvent 函数应该如何实现？在此先感谢您的帮助...

Answer 1

您可以将支票更改为:

if (!$document[0].onclick) { // Check in here
    $document[0].onclick = myListener;
}

这是 jsFiddle:http://jsfiddle.net/7mRQW/