WPF拖到、移动控件

只需2个事件和一个point变量即可：

 Point mouse_offset = , );
         void TC_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
         {
             mouse_offset = Mouse.GetPosition(e.Source as FrameworkElement);
         }

         void TC_MouseMove(object sender, MouseEventArgs e)
         {
             FrameworkElement element = sender as FrameworkElement;

             if (e.LeftButton == MouseButtonState.Pressed)
             {
                 element.Cursor = Cursors.Hand;
                 Point mousePos = Mouse.GetPosition(e.Source as FrameworkElement);

                 double nTop = Canvas.GetTop(element) + mousePos.Y - mouse_offset.Y;

                 double nLeft = Canvas.GetLeft(element) + mousePos.X - mouse_offset.X;

                 //防止控件被拖出容器。
                 )
                     nTop = ;
                 if (nTop >= (CI.Height - element.DesiredSize.Height))
                     nTop = CI.Height - element.DesiredSize.Height;
                 )
                     nLeft = ;
                 if (nLeft >= (CI.Width - element.DesiredSize.Width))
                     nLeft = CI.Width - element.DesiredSize.Width;

                 Canvas.SetLeft(element, nLeft);
                 Canvas.SetTop(element, nTop);
             }
             else
             {
                 element.Cursor = null;
             }
         }

2014-09-15 Update:

后来发现，WPF当中用到界面变换的应用很多，所以，把这个抽象成一个类，如果要使用这些变换，只需要调用这个方法就可以了。

1、用于附加变换的类。

     public class RYMatrix
     {
         public RYMatrix(FrameworkElement Container,
             MouseButtonEventHandler MouseDown = null,
             MouseButtonEventHandler MouseUp = null,
             MouseWheelEventHandler MouseWheel = null,
             MouseEventHandler MouseMove = null)
         {
             Container.MouseDown -= Container_MouseDown;
             Container.MouseUp -= Container_MouseUp;
             Container.MouseWheel -= Container_MouseWheel;
             Container.MouseMove -= Container_MouseMove;

             Container.MouseDown += Container_MouseDown;
             Container.MouseUp += Container_MouseUp;
             Container.MouseWheel += Container_MouseWheel;
             Container.MouseMove += Container_MouseMove;

             this.MouseDown = MouseDown;
             this.MouseUp = MouseUp;
             this.MouseWheel = MouseWheel;
             this.MouseMove = MouseMove;
         }

         MouseButtonEventHandler MouseDown;
         MouseButtonEventHandler MouseUp;
         MouseWheelEventHandler MouseWheel;
         MouseEventHandler MouseMove;
         private bool CanRotate { get; set; }
         private Point RotatePoint { get; set; }
         private DateTime LastClick { get; set; }
         private Point LastPoint { get; set; }

         private void Container_MouseUp(object sender, MouseButtonEventArgs e)
         {
             RotatePoint = , -);
             if (CanRotate)
             {
                 CanRotate = false;
             }
             if (MouseUp != null)
                 MouseUp(sender, e);
         }
         private void Container_MouseDown(object sender, MouseButtonEventArgs e)
         {
             FrameworkElement FE = sender as FrameworkElement;
             if (FE == null)
                 return;
             Point p = e.MouseDevice.GetPosition(FE);
              && RotatePoint.Y == -))
             {
                 RotatePoint = p;
             }
             else if (Mouse.LeftButton == MouseButtonState.Pressed)
             {
                 )
                 {
                     Matrix m = FE.RenderTransform.Value;
                     m.ScaleAtPrepend(1.1, 1.1, p.X, p.Y);
                     FE.RenderTransform = new MatrixTransform(m);
                 }
                 LastClick = DateTime.Now;
                 LastPoint = p;
             }
             else if (Mouse.RightButton == MouseButtonState.Pressed)
             {
             }
             if (MouseDown != null)
                 MouseDown(sender, e);
         }
         private void Container_MouseWheel(object sender, MouseWheelEventArgs e)
         {
             FrameworkElement FE = sender as FrameworkElement;
             Point p = e.MouseDevice.GetPosition(FE);
             Matrix m = FE.RenderTransform.Value;
             )
                 m.ScaleAtPrepend(1.1, 1.1, p.X, p.Y);
             else
                 m.ScaleAtPrepend( /  / 1.1, p.X, p.Y);
             FE.RenderTransform = new MatrixTransform(m);
             if (MouseWheel != null)
             {
                 MouseWheel(sender, e);
             }
         }
         private void Container_MouseMove(object sender, MouseEventArgs e)
         {
             FrameworkElement FE = sender as FrameworkElement;
             Point NowPoint = e.GetPosition(FE);
             if (e.LeftButton == MouseButtonState.Pressed)
             {
                 double resultY = NowPoint.Y - LastPoint.Y + (double)FE.GetValue(Canvas.TopProperty);
                 double resultX = NowPoint.X - LastPoint.X + (double)FE.GetValue(Canvas.LeftProperty);
                 Matrix m = FE.RenderTransform.Value;
                 m.TranslatePrepend(resultX, resultY);
                 FE.RenderTransform = new MatrixTransform(m);
                 FE.Cursor = Cursors.Hand;
             }
             else
                  && RotatePoint.Y != -)
                 {
                     Matrix m = FE.RenderTransform.Value;
                     if (NowPoint.X > RotatePoint.X)
                     {
                         m.RotateAtPrepend(0.1, RotatePoint.X, RotatePoint.Y);
                     }
                     else if (NowPoint.X < RotatePoint.X)
                     {
                         m.RotateAtPrepend(-0.1, RotatePoint.X, RotatePoint.Y);
                     }
                     Debug.WriteLine(RotatePoint.X + "|" + RotatePoint.Y);
                     FE.RenderTransform = new MatrixTransform(m);
                     LastPoint = NowPoint;
                 }
                 else if (Mouse.RightButton == MouseButtonState.Pressed)
                 {
                     Matrix m = FE.RenderTransform.Value;
                     Debug.WriteLine(RotatePoint.X + "|" + RotatePoint.Y);
                     FE.RenderTransform = new MatrixTransform(m);
                     LastPoint = NowPoint;
                 }
                 else
                 {
                     FE.Cursor = null;
                 }
             if (MouseMove != null)
             {
                 MouseMove(sender, e);
             }
         }
     }

2、调用这个类的前端页面：

 <Window x:Class="WPFClient.MainWindow"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         Title="MainWindow" Loaded="Window_Loaded">
     <Grid>
         <Canvas x:Name="Container"/>
     </Grid>
 </Window>

3、后台代码：

private void Window_Loaded(object sender, RoutedEventArgs e)
{
    Canvas CI = new Canvas();
    Canvas.SetTop(CI, );
    Canvas.SetLeft(CI, );
    Image I = new Image();
    I.Source = new BitmapImage(new Uri("http://d.hiphotos.baidu.com/image/pic/item/00e93901213fb80e68fd3dd734d12f2eb9389485.jpg", UriKind.Absolute));
    CI.Children.Add(I);
    new RuyeeSoft.WPF.UIProcess.RYMatrix(CI,null,new MouseButtonEventHandler((o,d)=>{ MessageBox.Show("xx");}));
}