Question

我正在尝试从Silverlight TreeView控件创建一个TreeView。我从WCF服务中提取数据，该服务来自EF。所有的数据都很好。我设置了页面，我可以在其中输入UserName，单击按钮，数据将填充TreeView中的第一代。所以，我正在动态构建TreeViewItems以放入我的TreeView中，并且每个都附加了一个Selected RoutedEventHandlers。当我单击其中一个TreeViewItem节点时，它将启动tvi_Selected函数，在该函数中我想在我刚刚选择的TreeViewItem下填充TreeViewItems。

当我在我的委托函数prox_GetChildMembersCompleted时遇到问题。我想不出办法在TreeViewItem上进行FindControl类型查找，我想将子TreeViewItem元素添加到。所以，我认为我只会创建一个受保护的字段，我将存储Header信息，因为它只包含UserName。我只需要能够通过Header或其他一些暗示我的方法访问特定的TreeViewItem。

你可以在我的Selected eventhandler中看到，我通过将发送者对象强制转换为TreeViewItem来获取Header信息。在tvi_Selected内部调用的委托函数prox_GetChildMembersCompleted中，发送方对象是WCFDataClient，因此我无法从该发送方获取相同的数据。即使你提出一种完全不同的方法，对此的任何见解都会非常有用。

<UserControl xmlns:controls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls"  
    xmlns:data="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data"
    x:Class="FloLOS2.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
    mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480">
  <Grid x:Name="LayoutRoot" Background="#5C7590">
        <StackPanel>
            <TextBox x:Name="txtUserName" Width="120" Margin="5"></TextBox>
            <TextBlock x:Name="txtFillBlock" Width="300" Margin="5" Foreground="White" Text="Change me"></TextBlock> 
            <Button x:Name="btnSubmit" Margin="5" Content="Get Frontline" Width="120" Click="btnSubmit_Click" />
            <data:DataGrid x:Name="MembersGrid" Margin="5"></data:DataGrid>
            <controls:TreeView x:Name="MembersTree" Margin="5"></controls:TreeView>
        </StackPanel>
    </Grid>
</UserControl>



namespace FloLOS2
{
    public partial class MainPage : UserControl
    {
        string sParentID;

        public MainPage()
        {
            InitializeComponent();
        }

        private void btnSubmit_Click(object sender, RoutedEventArgs e)
        {
            GetMyDataRef.GetMyDataClient prox = new FloLOS2.GetMyDataRef.GetMyDataClient();
            prox.GetMembersCompleted += new EventHandler<FloLOS2.GetMyDataRef.GetMembersCompletedEventArgs>(prox_GetMembersCompleted);
            prox.GetMembersAsync(txtUserName.Text);
        }

        void prox_GetMembersCompleted(object sender, FloLOS2.GetMyDataRef.GetMembersCompletedEventArgs e)
        {
            GetMyDataRef.Member[] members = e.Result.ToArray();

            foreach (var x in members)
            {
                TreeViewItem tvi = new TreeViewItem() { Header = x.UserName };
                tvi.Selected += new RoutedEventHandler(tvi_Selected);
                MembersTree.Items.Add(tvi);
            }

            //MembersTree.Items.Add(tvi);
        }

        void prox_GetChildMembersCompleted(object sender, FloLOS2.GetMyDataRef.GetMembersCompletedEventArgs e)
        {
            GetMyDataRef.Member[] members = e.Result.ToArray();
            TreeViewItem tviParent = new TreeViewItem();
            // *** Find TreeViewItem control based on Header  ***

            foreach (var x in members)
            {
                TreeViewItem tviChild = new TreeViewItem() { Header = x.UserName };
                tviChild.Selected += new RoutedEventHandler(tvi_Selected);
                tviParent.Items.Add(tviChild);
            }

        }

        void tvi_Selected(object sender, RoutedEventArgs e)
        {
            try
            {

                TreeViewItem item = (TreeViewItem)sender;
                txtFillBlock.Text = item.Header.ToString();
                sParentID = item.Header.ToString();

                GetMyDataRef.GetMyDataClient prox = new FloLOS2.GetMyDataRef.GetMyDataClient();
                prox.GetMembersCompleted += new EventHandler<FloLOS2.GetMyDataRef.GetMembersCompletedEventArgs>(prox_GetChildMembersCompleted);
                prox.GetMembersAsync(item.Header.ToString());

            }
            catch (Exception ex)
            {
                txtFillBlock.Text = ex.InnerException.ToString();
            }
        }


    }
}

Answer 1

我想出了办法。我去为动态生成的TreeViewItems分配了一个Name作为UserName。我还将发件人UserName存储在受保护的字符串中，然后调用此行代码以获取父TreeViewItem：

    TreeViewItem tviParent = (TreeViewItem)LayoutRoot.FindName(sParentID);

谢谢你会得到很棒的答案！：）

通过Header查找Silverlight TreeViewItem控件

1 个答案: