WPF实现控件拖动的示例代码

<Grid Name="gd">  <Button Width=90 Height=30 Name="btn">button</Button></Grid>

public SystemMap(){   InitializeComponent();   btn.MouseLeftButtonDown += btn_MouseLeftButtonDown;   btn.MouseMove += btn_MouseMove;   btn.MouseLeftButtonUp += btn_MouseLeftButtonUp;}

Point pos = new Point();void btn_MouseLeftButtonDown(object sender, MouseButtonEventArgs e){  Button tmp = (Button)sender;  pos = e.GetPosition(null);  tmp.CaptureMouse();  tmp.Cursor = Cursors.Hand;}

void btn_MouseMove(object sender, MouseEventArgs e){   if (e.LeftButton==MouseButtonState.Pressed)   {      Button tmp = (Button)sender;      double dx = e.GetPosition(null).X - pos.X + tmp.Margin.Left;      double dy = e.GetPosition(null).Y - pos.Y + tmp.Margin.Top;      tmp.Margin = new Thickness(dx, dy, 0, 0);      pos = e.GetPosition(null);   }}

void btn_MouseLeftButtonUp(object sender, MouseButtonEventArgs e){     Button tmp = (Button)sender;     tmp.ReleaseMouseCapture();}