为什么不能删除EventListener

Question

code link

I want to remove mouseover event when mouseup event triggers, but why can't revomeEventListener and how to fix it,looks like this is my weak part in javascript.

Answer 1

In your fnDown you set the event listener to be on the dragBox but then you try to remove it from the dragArea later on. You need to attach the listener to the dragArea if that's where you plan to remove it from. This function works as expected.

    Drag.prototype.fnDown = function (e) {
        this.diff.x = e.clientX - this.dragBox.offsetLeft
        this.diff.y = e.clientY - this.dragBox.offsetTop
        this.dragArea.addEventListener('mousemove', this.fnMove,false)
    }

Working example: http://jsbin.com/dugoxeziho/1/edit?html,output