How to select TreeViewItemAdv using key input in WPF TreeViewAdv?

5 mins read

As like in Microsoft Office application, end users would like an option in WPF TreeViewAdv to select TreeViewItemAdv, just by typing its content in Keyboard. But there is no default option for this requirement in TreeViewAdv and it can be achieved by handling its PreviewKeyDown event.

The following code snippets demonstrates the same.

C#:

/// <summary>
/// Occurs when Key is pressed
/// </summary>
/// <param name="sender">TreeViewAdv</param>
/// <param name="e">KeyEventArgs</param>
void treeview_PreviewKeyDown(object sender, KeyEventArgs e)
{
    List<TreeViewItemAdv> samekey = new List<TreeViewItemAdv>();
    TreeViewItemAdv selecteditemlevel1 = treeview.Items[0] as TreeViewItemAdv;

    if (PreviousKey != e.Key.ToString())
    {
        PreviousselectedItem = null;
    }

    for (int i = 0; i < selecteditemlevel1.Items.Count; i++)
    {
        if (selecteditemlevel1.Items[i].ToString().StartsWith(e.Key.ToString()))
        {
            samekey.Add(selecteditemlevel1.Items[i] as TreeViewItemAdv);
        }
    }

    for (int i = 0; i < samekey.Count; i++)
    {
        if (PreviousselectedItem == null || PreviousselectedItem == (samekey[i] as TreeViewItemAdv))
        {
            loopcompleted = true;
        }

        if (!(samekey[i] as TreeViewItemAdv).IsSelected && loopcompleted)
        {
            this.treeview.SelectedItems.Clear();
            (samekey[i] as TreeViewItemAdv).IsSelected = true;
            PreviousselectedItem = (samekey[i] as TreeViewItemAdv);
            loopcompleted = false;
            PreviousKey = e.Key.ToString();
            
            if (samekey.Count - 1 == i)
            {
                PreviousselectedItem = null;
            }
            return;
        }
    }
    samekey.Clear();
}

VB:

''' <summary>
''' Occurs when Key is pressed
''' </summary>
''' <param name="sender">TreeViewAdv</param>
''' <param name="e">KeyEventArgs</param>
Private Sub treeview_PreviewKeyDown(ByVal sender As Object, ByVal e As KeyEventArgs)
    Dim samekey As New List(Of TreeViewItemAdv)()
    Dim selecteditemlevel1 As TreeViewItemAdv = TryCast(treeview.Items(0), TreeViewItemAdv)

    If PreviousKey <> e.Key.ToString() Then
        PreviousselectedItem = Nothing
    End If

    For i As Integer = 0 To selecteditemlevel1.Items.Count - 1
        If selecteditemlevel1.Items(i).ToString().StartsWith(e.Key.ToString()) Then
            samekey.Add(TryCast(selecteditemlevel1.Items(i), TreeViewItemAdv))
        End If
    Next i

    For i As Integer = 0 To samekey.Count - 1
        If PreviousselectedItem Is Nothing OrElse PreviousselectedItem Is (TryCast(samekey(i), TreeViewItemAdv)) Then
            loopcompleted = True
        End If

        If Not (TryCast(samekey(i), TreeViewItemAdv)).IsSelected AndAlso loopcompleted Then
            Me.treeview.SelectedItems.Clear()
            TryCast(samekey(i), TreeViewItemAdv).IsSelected = True
            PreviousselectedItem = (TryCast(samekey(i), TreeViewItemAdv))
            loopcompleted = False
            PreviousKey = e.Key.ToString()

            If samekey.Count - 1 = i Then
                PreviousselectedItem = Nothing
            End If
            Return
        End If
    Next i
    
    samekey.Clear()
End Sub

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How to select TreeViewItemAdv using key input in WPF TreeViewAdv?

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