1 <Canvas Name="movBg">   2             <Canvas.Background>   3                 <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">   4                     <GradientStop Color="White" Offset="0" />   5                     <GradientStop Color="#FFF5FF00" Offset="1" />   6                 </LinearGradientBrush>   7             </Canvas.Background>   8             <Canvas Canvas.Top="50" Canvas.Left="50"  Height="100" HorizontalAlignment="Left" Name="mov" VerticalAlignment="Top" Width="200" MouseLeftButtonDown="mov_MouseLeftButtonDown" MouseLeftButtonUp="mov_MouseLeftButtonUp" MouseMove="mov_MouseMove" MouseWheel="mov_MouseWheel" MaxWidth="300" MaxHeight="300">   9                 <Border BorderThickness="1" BorderBrush="Black" Width="{Binding ElementName=mov,Path=Width}" Height="{Binding ElementName=mov,Path=Height}" MaxWidth="{Binding ElementName=mov,Path=MaxWidth}" MaxHeight="{Binding ElementName=mov,Path=MaxHeight}"></Border>  10                 <Canvas.Background>  11                     <LinearGradientBrush EndPoint="1,0.5" StartPoint="0,0.5">  12                         <GradientStop Color="White" Offset="0" />  13                         <GradientStop Color="#FFD679F2" Offset="1" />  14                     </LinearGradientBrush>  15                 </Canvas.Background>  16             </Canvas>  17 </Canvas>  

  1 #region 拖动选区,滚轴改变大小    2         //鼠标相对于被拖动的Canvas控件mov的坐标    3         Point childPoint = new Point();    4         //鼠标相对于作为容器的Canvas控件movBg的坐标    5         Point prevPoint = new Point();    6     7         private void mov_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)    8         {    9             childPoint = e.GetPosition(mov);   10         }   11    12         private void mov_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)   13         {   14             Canvas c = sender as Canvas;   15             Rect rc = new Rect(1, 1, movBg.ActualWidth, movBg.ActualHeight);   16             Rect childRc = new Rect(Canvas.GetLeft(c), Canvas.GetTop(c), c.ActualWidth, c.ActualHeight);   17             if (!rc.Contains(childRc))   18             {   19                 childRc = AutoResize(rc, childRc);   20                 c.SetValue(Canvas.LeftProperty, childRc.Left);   21                 c.SetValue(Canvas.TopProperty, childRc.Top);   22                 c.Width = childRc.Width;   23                 c.Height = childRc.Height;   24             }   25             c.ReleaseMouseCapture();   26         }   27    28         private void mov_MouseMove(object sender, MouseEventArgs e)   29         {   30             if (e.LeftButton == MouseButtonState.Pressed)   31             {   32                 Canvas c = sender as Canvas;   33    34                 prevPoint = e.GetPosition(movBg);   35                 double x = prevPoint.X - childPoint.X;   36                 double y = prevPoint.Y - childPoint.Y;   37    38                 Rect rc = new Rect(1, 1, movBg.ActualWidth, movBg.ActualHeight);   39                 Rect childRc = new Rect(Canvas.GetLeft(c), Canvas.GetTop(c), c.ActualWidth, c.ActualHeight);   40                 if (!rc.Contains(childRc))   41                 {   42                     childRc = AutoResize(rc, childRc);   43                     c.SetValue(Canvas.LeftProperty, childRc.Left);   44                     c.SetValue(Canvas.TopProperty, childRc.Top);   45                     c.Width = childRc.Width;   46                     c.Height = childRc.Height;   47                     c.ReleaseMouseCapture();   48                 }   49                 else   50                 {   51                     c.SetValue(Canvas.LeftProperty, prevPoint.X - childPoint.X);   52                     c.SetValue(Canvas.TopProperty, prevPoint.Y - childPoint.Y);   53                     c.CaptureMouse();   54                 }   55             }   56         }   57    58         private Rect AutoResize(Rect outerRc, Rect innerRc)   59         {   60             double with = innerRc.Width;   61             double height = innerRc.Height;   62    63             if (innerRc.Left < outerRc.Left)   64             {   65                 innerRc.X = outerRc.Left + 1;   66                 innerRc.Width = with;   67             }   68             if (innerRc.Right > outerRc.Right)   69             {   70                 innerRc.X = outerRc.Right - with - 1;   71                 innerRc.Width = with;   72             }   73             if (innerRc.Top < outerRc.Top)   74             {   75                 innerRc.Y = outerRc.Top + 1;   76                 innerRc.Height = height;   77             }   78             if (innerRc.Bottom > outerRc.Bottom)   79             {   80                 innerRc.Y = outerRc.Bottom - height - 1;   81                 innerRc.Height = height;   82             }   83             return innerRc;   84         }   85    86         private void mov_MouseWheel(object sender, MouseWheelEventArgs e)   87         {   88             double val = e.Delta * 0.001;   89             double wl = mov.Width * (val / 0.12) * 0.02;   90             double hl = mov.Height * (val / 0.12) * 0.02;   91    92             if ((Canvas.GetLeft(mov) - wl/2.0) > 0 && (Canvas.GetLeft(mov) + wl + mov.Width) <= movBg.ActualWidth &&   93                 (Canvas.GetTop(mov) - hl/2.0) > 0 && (Canvas.GetTop(mov) + hl + mov.Height) <= movBg.ActualHeight &&   94                 (mov.Width + wl) < mov.MaxWidth && (mov.Height + hl) < mov.MaxHeight)   95             {   96                 mov.SetValue(Canvas.LeftProperty, Canvas.GetLeft(mov) - wl / 2.0);   97                 mov.SetValue(Canvas.TopProperty, Canvas.GetTop(mov) - hl / 2.0);   98                 mov.Width += wl;   99                 mov.Height += hl;  100   101             }  102             return;  103         }  104         #endregion