WPF的DataGrid缩放到鼠标的位置

Question

我有LayoutTransform被绑定到一个滑块一样，一个DataGrid：

<DataGrid.LayoutTransform> 
      <ScaleTransform 
       ScaleX="{Binding ElementName=MySlider, Path=Value}" 
       ScaleY="{Binding ElementName=MySlider, Path=Value}" /> 
     </DataGrid.LayoutTransform> 
    </DataGrid> 

    <Slider x:Name="MySlider" 
      Minimum="0.3" 
      Maximum="2.0" 
      SmallChange="0.1" 
      LargeChange="0.1" 
      Value="1.0" 
      IsSnapToTickEnabled="True" 
      TickFrequency="0.1" 
      TickPlacement="TopLeft" 
      VerticalAlignment="Bottom" 
      HorizontalAlignment="Right" 
      Width="200" 
      Margin="0,0,61,0" /> 

    <TextBlock Name="Lstate" 
       Text="{Binding ElementName=MySlider, Path=Value, StringFormat={}{0:P0}}" 
       VerticalAlignment="Bottom" 
       HorizontalAlignment="Right" 
       Width="50" Height="20" 
       Margin="0,0,0,1" /> 

现在，在代码中，我用下面的代码的PreviewMouseWheel事件：

bool handle = (Keyboard.Modifiers & ModifierKeys.Control) > 0; 
     if (!handle) 
      return; 

     double value; 

     if (e.Delta > 0) 
      value = 0.1; 
     else 
      value = -0.1; 

     MySlider.Value += value; 

而我的问题是：如何滚动到像AutoCad或其他程序的实际鼠标位置？

感谢

对不起我的英文不好...

Answer 1

我现在有一个非常非常好的解决方案：

VirtualizingStackPanel.IsVirtualizing="True" 
VirtualizingStackPanel.VirtualizationMode="Standard" 
EnableColumnVirtualization="False" 
EnableRowVirtualization="True" 
ScrollViewer.CanContentScroll="True" 

    private void Data_OnPreviewMouseWheel(object sender, MouseWheelEventArgs e) 
    { 
     // Scroll to Zoom 
     if (Keyboard.IsKeyDown(Key.LeftCtrl) || Keyboard.IsKeyDown(Key.RightCtrl)) 
     { 
      // Prevent scroll 
      e.Handled = true; 

      var scrollview = FindVisualChild<ScrollViewer>(Data); 
      if (scrollview != null) 
      { 
       // The "+20" are there to account for the scrollbars... i think. Not perfectly accurate. 
       var relativeMiddle = new Point((Data.ActualWidth + 20)/2 + (Mouse.GetPosition(Data).X - Data.ActualWidth/2), (Data.ActualHeight + 20)/2 + (Mouse.GetPosition(Data).Y - Data.ActualHeight/2)); 
       var oldLocation = Data.LayoutTransform.Transform(Data.PointFromScreen(relativeMiddle)); 

       // Zoom 
       MySlider.Value += (e.Delta > 0) ? MySlider.TickFrequency : -MySlider.TickFrequency; 

       // Scroll 
       var newLocation = Data.LayoutTransform.Transform(Data.PointFromScreen(relativeMiddle)); 

       // Calculate offset 
       var shift = newLocation - oldLocation; 

       if (scrollview.CanContentScroll) 
       { 
        // Scroll to the offset (Item) 
        scrollview.ScrollToVerticalOffset(scrollview.VerticalOffset + shift.Y/scrollview.ViewportHeight); 
       } 
       else 
       { 
        // Device independent Pixels 
        scrollview.ScrollToVerticalOffset(scrollview.VerticalOffset + shift.Y); 
       } 

       // Device independent Pixels 
       scrollview.ScrollToHorizontalOffset(scrollview.HorizontalOffset + shift.X); 
      } 
     } 
    } 

它缩放到鼠标的位置上Datagrid的使用和不使用虚拟化。