无法在GoogleMaps中删除事件监听器

Question

我在单击按钮时注册了一个事件：

 var paths=[];
 var mapPolylineListener=e.addEventToTarget(map,'click',function(event){
    //keep adding points to the array
    //draw the polyline if there are two points
    //extend the polyline with this point once it has been drawn 
 }

 e.addEventToTargetOnce(map,'rightclick',function(event){
    console.log('Polyline right click event called');
    if(typeof mapPolylineListener!='undefined')
    {
      console.log('stop drawing the map listener');
          //do stuff here like encoding to geometry and making AJAX calls
      paths=[];
      mapPolylineListener=void 0;
    }               

事件模块定义了以下功能：

  addEventToTarget:function(onWhat,eventType,fn)
  {
     gmaps.event.addListener(onWhat,eventType,fn);
  }

  addEventToTargetOnce:function(onWhat,eventType,fn)
  {
    gmaps.event.addListenerOnce(onWhat,eventType,fn);
  }

我正在使用requirejs模块，并使用模块来指定功能：

 e=gmaps.event;
 gmaps=window.google.maps;

在我的控制台中，它显示：

  Polyline right click event called

而且检查似乎总是失败

 if(typeof mapPolylineListener!='undefined')

所以，我尝试做一个!=null和if(mapPolylineListener)检查两者都失败了。

如何解决此问题，以便执行if块中的代码？

Answer 1

我不确定requirejs模块的工作方式...因为addEventToTarget没有返回任何内容，所以我将更改以下内容：

addEventToTarget:function(onWhat,eventType,fn)
{
    var handle = gmaps.event.addListener(onWhat,eventType,fn);
    return handle;
}

然后在e.addEventToTargetOnce(map,'rightclick',function(event){...调用removeListener(mapPolylineListener)