.net中实现拖拽控件

.net中实现拖拽控件

         private   int  tX  =   0 ;          private   int  tY  =   0 ;          private   void  btn_MouseDown( object  sender, System.Windows.Forms.MouseEventArgs e)          {             this.tX = e.X;             this.tY = e.Y;             this.btn.MouseMove += new System.Windows.Forms.MouseEventHandler(this.btn_MouseMove);         }          private   void  btn_MouseUp( object  sender, System.Windows.Forms.MouseEventArgs e)          {             this.btn.MouseMove -= new System.Windows.Forms.MouseEventHandler(this.btn_MouseMove);         }          private   void  btn_MouseMove( object  sender, System.Windows.Forms.MouseEventArgs e)          {             this.btn.Location = new System.Drawing.Point(this.btn.Location.X + e.X - this.tX, this.btn.Location.Y + e.Y - this.tY);         }