WPF TextBox.SelectAll () doesn't work

Question

I have used the following template in my project:

<DataTemplate 
    x:Key="textBoxDataTemplate">
    <TextBox 
        Name="textBox"
        ToolTip="{Binding RelativeSource={RelativeSource Self}, Path=(Validation.Errors)[0].ErrorContent}"
        Tag="{Binding}"
        PreviewKeyDown="cellValueTextBoxKeyDown">
        <TextBox.Text>
            <MultiBinding
                Converter="{StaticResource intToStringMultiConverter}">
                <Binding 
                    Path="CellValue"
                    Mode="TwoWay">
                        <Binding.ValidationRules>
                            <y:MatrixCellValueRule 
                                MaxValue="200" />
                        </Binding.ValidationRules>
                </Binding>
                <Binding 
                    RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type y:MatrixGrid}}" 
                    Path="Tag"
                    Mode="OneWay" />
            </MultiBinding>
        </TextBox.Text>
    </TextBox>
</DataTemplate>

I used this template to create an editable matrix for the user. The user is able to navigate from cell to cell within the matrix and I would like to highlight the data in the selected textbox but it doesn't work. I called TextBox.Focus () and TextBox.SelectAll () to achieve the effect but nothing. The Focus () works but the text never gets highlighted.

Any help is welcome and appreciated.

Answer 1

Okay, if anyone is interested, the solution to this problem of mine was to include the statement e.Handled = true; in the event handler method where the textBox.SelectAll() and textBox.Focus() are called.

The problem was that I attached an event handler to the textbox's PreviewKeyDown event which handles a tunneling event and probably the SelectAll() and Focus() calls are ignored without calling the e.Handled = true; statement.

Hope it'll help someone.