2019/06/06

1. DOM2级事件：addEventListener("click",function(),false),removeEventListener()
   false：冒泡
   
   IE事件：attachEVent("click",function()),detachEvent("click",function())
   默认冒泡，支持IE事件处理程序的浏览器有IE和Opera

2. 跨浏览器的事件处理程序：

var EventUtil = {
  addHandler:function(elemwnt,type,handler){
    if(element.addEventListener){
      element.addEventListener(type,handler,false);
    }else if(element.attachEvent){
      element.attachEvent("on" + type,handler);
    }else{
      element["on" + type] = handler;
    }
  },
  removeHandler:function(elemwnt,type,handler){
    if(element.removeEventListener){
      element.removeEventListener(type,handler,false);
    }else if(element.detachEvent){
      element.detachEvent("on" + type,handler);
    }else{
      element["on" + type] = null;
    }
  }
};

3. 跨浏览器的事件对象:

var EventUtil = {
  addHandler:function(elemwnt,type,handler){
    if(element.addEventListener){
      element.addEventListener(type,handler,false);
    }else if(element.attachEvent){
      element.attachEvent("on" + type,handler);
    }else{
      element["on" + type] = handler;
    }
  },
  getEvent:function(event){
    return event ? event : window.event;
  },
  getTarget:function(event){
    return event.target || event.srcElement;
  },
  preeventDefault:function(event){
    if(event.preventDefault){
      event.preventDefault();
    }else{
      event.returnValue = false;
    }
  },

  removeHandler:function(elemwnt,type,handler){
    if(element.removeEventListener){
      element.removeEventListener(type,handler,false);
    }else if(element.detachEvent){
      element.detachEvent("on" + type,handler);
    }else{
      element["on" + type] = null;
    }
  },
  stopPropagation:function(event){
    if(event.stopPropagation){
      event.stopPropagation();
    }else{
      event.cancelBubble = true;
    }
  }
};