通过扩展Silverlight的控件DataGrid,使其垂直滚动条支持鼠标滑轮

      Silverlight3及以前的版本的DataGrid,ListBox,TreeView的垂直滚动条都是不支持鼠标滑轮的，不知道SL4支持不？本文通过扩展DataGrid来支持鼠标滑轮。使DataGrid的使用效果更好，使用户使用起来更方便

     以下是扩展的方法

创建 Silverlight 工程

使用 Visual Studio 2008 and 创建一个新的 Silverlight 3 工程. 命名为 MouseScroll.



在Silverlight工程中新增一个类，命名为ScrollDataGrid.cs，让这个类继承SL3的DataGrid,代码如下
public class ScollDataGrid: DataGrid
{
}

你必须在程序中添加下面三个DLL
using System.Windows.Automation.Peers;
using System.Windows.Automation.Provider;
using System.Windows.Automation;

下面的方法就是实现DataGrid支持鼠标滑轮的方法

protected override void OnMouseWheel(MouseWheelEventArgs e)
{
    base.OnMouseWheel(e);
    //从datagrid取得AutomationPeer
   AutomationPeer automationPeer = FrameworkElementAutomationPeer.FromElement(this);
    if (automationPeer == null)
    {
        automationPeer = FrameworkElementAutomationPeer.CreatePeerForElement(this);
    }
    //得到 datagrid的scroll provider 
    IScrollProvider scrollProvider = automationPeer.GetPattern(PatternInterface.Scroll) as IScrollProvider;
    if (scrollProvider != null)
    {
        ScrollAmount scrollAmount = ScrollAmount.NoAmount;
        if (e.Delta < 0)
            scrollAmount = ScrollAmount.SmallIncrement;//向下滑动

        else if (e.Delta > 0)
            scrollAmount = ScrollAmount.SmallDecrement;//向上滑动

        if (scrollProvider.VerticallyScrollable)
        {
            scrollProvider.Scroll(ScrollAmount.NoAmount, scrollAmount);
        }
    }
}

在MainPage.xaml 新增如下命名空间:

xmlns:local="clr-namespace:MouseScroll"

然后再新增如下代码
<local:ScollDataGrid x:Name="myDataGrid" Height="100" HorizontalAlignment="Left" VerticalAlignment="Top" Width="271" Margin="20,20,0,0" />

现在我们新增一个类，然后向集合中新增一些数据来填充DataGrid

class PersonalData
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public int Age { get; set; }
}

public partial class MainPage : UserControl
{
    List<PersonalData> myList;
    public MainPage()
    {
        InitializeComponent();
        #region Dummy List
        myList = new List<PersonalData> 
        {
            new PersonalData{ FirstName="FirstName1", LastName="LastName1", Age=39},
            new PersonalData{ FirstName="FirstName2", LastName="LastName2", Age=40},
            new PersonalData{ FirstName="FirstName3", LastName="LastName3", Age=41},
            new PersonalData{ FirstName="FirstName4", LastName="LastName4", Age=42},
            new PersonalData{ FirstName="FirstName5", LastName="LastName5", Age=43},
            new PersonalData{ FirstName="FirstName6", LastName="LastName6", Age=44},
            new PersonalData{ FirstName="FirstName7", LastName="LastName7", Age=45},
            new PersonalData{ FirstName="FirstName8", LastName="LastName8", Age=46},
            new PersonalData{ FirstName="FirstName9", LastName="LastName9", Age=47},
            new PersonalData{ FirstName="FirstName10", LastName="LastName10", Age=48},
            new PersonalData{ FirstName="FirstName11", LastName="LastName11", Age=49},
            new PersonalData{ FirstName="FirstName12", LastName="LastName12", Age=50},
            new PersonalData{ FirstName="FirstName13", LastName="LastName13", Age=51},
            new PersonalData{ FirstName="FirstName14", LastName="LastName14", Age=52},
        }; 
        #endregion
        myDataGrid.ItemsSource = myList;
    }
}

现在运行程序，那么垂直滚动条就可以用鼠标滑轮滑动了


      希望以上代码对大家有帮助，大家也可以根据此代码来扩展ListBox,TreeView。其中第三方控件已经修补这个BUG

      另外，如果大家觉得有用，就支持一下，谢谢