【Silverlight】Bing Maps开发应用与技巧五：实现图钉（Pushpin）的可拖放性（Draggable）扩展

System.Object 
   System.Windows.DependencyObject 
     System.Windows.UIElement 
       System.Windows.FrameworkElement 
         System.Windows.Controls.Control 
           System.Windows.Controls.ContentControl 
            Microsoft.Maps.MapControl.Pushpin

< m:Map  x:Name ="myMap"  Margin ="0,0,0,0"  CredentialsProvider =" {StaticResource MyCredentials} " >

  <m:MapLayer x:Name="MapLayer">　　　　
     < m:Pushpin  Location ="29.5076372217973, 106.489384971208"  Content ="D" ></ m:Pushpin >

 </m:MapLayer>
</ m:Map >

public   class  DraggablePushpin : Microsoft.Maps.MapControl.Pushpin
{
     ///   <summary>
     ///  是否正在拖放
     ///   </summary>
     private   bool  IsDragging  =   false ;
     ///   <summary>
     ///  鼠标拖放
     ///   </summary>
     private  EventHandler < MapMouseDragEventArgs >  MapMouseDragHandler;
     ///   <summary>
     ///  鼠标左键弹起
     ///   </summary>
     private  MouseButtonEventHandler MapMouseLeftButtonUpHandler;
     ///   <summary>
     ///  鼠标移动
     ///   </summary>
     private  MouseEventHandler MapMouseMoveHandler;
}

[ScriptableMemberAttribute] 
public   override   event  EventHandler < MapMouseDragEventArgs >  MousePan;

// 地图控件的鼠标移动事件定义
public   abstract   event  MouseEventHandler MouseMove;

///   <summary>
///  功能描述：自定义扩展图钉类，实现可拖拽图钉。
///  编    写：Beniao
///  时    间：2010年5月31日22:37:46
///   </summary>
public   class  DraggablePushpin : Microsoft.Maps.MapControl.Pushpin
{
     ///   <summary>
     ///  是否正在拖放
     ///   </summary>
     private   bool  IsDragging  =   false ;
     ///   <summary>
     ///  鼠标拖放
     ///   </summary>
     private  EventHandler < MapMouseDragEventArgs >  MapMouseDragHandler;
     ///   <summary>
     ///  鼠标左键弹起
     ///   </summary>
     private  MouseButtonEventHandler MapMouseLeftButtonUpHandler;
     ///   <summary>
     ///  鼠标移动
     ///   </summary>
     private  MouseEventHandler MapMouseMoveHandler;

     protected   override   void  OnMouseLeftButtonDown(MouseButtonEventArgs e)
    {
         // 因为图钉是添加在MapLayer上的
        var parentLayer  =   this .Parent  as  MapLayer;
         if  (parentLayer  !=   null )
        {
             // MapLayer是Map的一个子对象
            var parentMap  =  parentLayer.ParentMap;
             if  (parentMap  !=   null )
            {
                 if  ( this .MapMouseDragHandler  ==   null ) 
                {
                     this .MapMouseDragHandler  =   new  EventHandler < MapMouseDragEventArgs > (ParnetMap_MousePan);
                    parentMap.MousePan  +=   this .MapMouseDragHandler;
                }

                 if  ( this .MapMouseLeftButtonUpHandler  ==   null )
                {
                     this .MapMouseLeftButtonUpHandler  =   new  MouseButtonEventHandler(PrentMap_MouseLeftButtonUp);
                    parentMap.MouseLeftButtonUp  +=   this .MapMouseLeftButtonUpHandler;
                }

                 if  ( this .MapMouseMoveHandler  ==   null )
                {
                     this .MapMouseMoveHandler  =   new  MouseEventHandler(PrentMap_MouseMove);
                    parentMap.MouseMove  +=   this .MapMouseMoveHandler;
                }
            }
        }
         this .IsDragging  =   true ;

         base .OnMouseLeftButtonDown(e);
    }

     private   void  ParnetMap_MousePan( object  sender, MapMouseDragEventArgs e)
    {
         if  ( this .IsDragging)
        {
            e.Handled  =   true ;
        }
    }

     private   void  PrentMap_MouseLeftButtonUp( object  sender, MouseButtonEventArgs e)
    {
         this .IsDragging  =   false ;
    }

     private   void  PrentMap_MouseMove( object  sender, MouseEventArgs e)
    {
        var map  =  sender  as  Map;
         if  ( this .IsDragging)
        {
            var mousePosition  =  e.GetPosition(map);
            var geoPosition  =  map.ViewportPointToLocation(mousePosition);

　　　　　　　//重新定位图钉位置
             this .Location  =  geoPosition;
        }
    }
}

private   void  AddPushPin()
{
     for  ( int  i  =   1 ; i  <   501 ; i ++ )
    {
        MapLayer.AddChild( new  DraggablePushpin() 

        { 

           Content  =  i.ToString() 

        }, 

            new  Location(i  /   4 , i  /   2 )

        );
    }
}