Find a Silverlight TreeViewItem Control Header

Question

I am trying to create a TreeView from a Silverlight TreeView control. My data is extracted from the WCF service, which is pulled from EF. All data is in order. I have a page installed, where I can enter the username, click the button, and the data will populate the first generation in TreeView. Thus, I dynamically build TreeViewItems to fit into my TreeView with the selected RoutedEventHandlers attached to each of them. When I click on one of the TreeViewItem nodes, it runs the tvi_Selected function, in which I want to populate the TreeViewItems under the TreeViewItem that I just selected.

I ran into a problem when I am in my prox_GetChildMembersCompleted delegate function. I cannot understand the search method of type FindControl in TreeViewItem that I want to add to the elements of the child TreeViewItem. So, I thought that I was just creating a protected field where I would store the header information, because it contains only the username. I just need to have access to a specific TreeViewItem element by a header or another method that refers to me.

You can see that in the Selected Selected handler I get the header information by discarding the sender object of the TreeViewItem. In the prox_GetChildMembersCompleted delegate function, which is called inside tvi_Selected, the sending object is WCFDataClient, so I cannot get the same data from this sender. Any understanding of this would be greatly appreciated, even if you suggest a completely different method.

<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

I figured out a way to do this. I went and assigned the name to the dynamically generated TreeViewItems as UserName. I also saved the sender username in a secure string, and then called this line of code to get the parent TreeViewItem:

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

, !:)