javascript - 禁用插件时，自举插件中的removeEventListener不起作用

我已经注意到，在禁用引导加载项之后，removeEventListener似乎并没有删除侦听器，我无法弄清原因。

let contextMenu = window.document.getElementById('contentAreaContextMenu');
if (contextMenu) {
  contextMenu.addEventListener('popupshowing',
            this.contextPopupShowing.bind(this), false);
  // added this to make sure they refer to the same function
  console.log(this.contextPopupShowing.toString());
}

然后禁用插件

console.log(this.contextPopupShowing.toString()); // same as above
this.contextMenu.removeEventListener('popupshowing',
            this.contextPopupShowing.bind(this), false);
// just showing that 'this' is working
this.contextMenu.removeChild(this.menuitem);

终于...

contextPopupShowing: function() {
  // logs even after removeEventListener
  console.log('contextPopupShowing called');
  // more code
},

最佳答案

因为它是bind版本。您要做的是：

添加时：

let contextMenu = window.document.getElementById('contentAreaContextMenu');
if (contextMenu) {
  this.contextPopupShowingBound = this.contextPopupShowing.bind(this);
  contextMenu.addEventListener('popupshowing',
            this.contextPopupShowingBinded, false);
  // added this to make sure they refer to the same function
  console.log(this.contextPopupShowing.toString());
}

然后禁用插件

console.log(this.contextPopupShowing.toString()); // same as above
this.contextMenu.removeEventListener('popupshowing',
            this.contextPopupShowingBound, false);
// just showing that 'this' is working
this.contextMenu.removeChild(this.menuitem);

终于...

contextPopupShowing: function() {
  // logs even after removeEventListener
  console.log('contextPopupShowing called');
  // more code
},

我敢肯定，您不能在bind中使用removeEventListener。

请参阅以下主题的出色主题：Removing event listener which was added with bind