How to select all text in TextBox WPF when focused?

Question

I have tried the below code to select all text in textbox when focus. But this is not working.

XAML:

        <TextBox Text="test1" Width="100" Height="200"  
           GotFocus="TextBox_GotFocus"></TextBox>

c#:

private void TextBox_GotFocus(object sender, RoutedEventArgs e)
        {
            (sender as TextBox).SelectAll();    
            //(sender as TextBox).Select(0, (sender as TextBox).Text.Length);
            (sender as TextBox).Focus();  
            e.Handled = true;
        }

I have tried with asynchronous also. Surf lots , but nothing works. Please suggest?

Duplicate `https://stackoverflow.com/questions/660554/how-to-automatically-select-all-text-on-focus-in-wpf-textbox` — Afnan Ahmad, Nov 27 '18 at 13:35
Possible duplicate of [How to automatically select all text on focus in WPF TextBox?](https://stackoverflow.com/questions/660554/how-to-automatically-select-all-text-on-focus-in-wpf-textbox) — Antoine V, Nov 27 '18 at 13:51

score 18 · Answer 1 · answered Nov 27 '18 at 14:34

18

You could use the dispatcher:

private void TextBox_GotFocus(object sender, RoutedEventArgs e)
{
    TextBox textBox = (TextBox)sender;
    textBox.Dispatcher.BeginInvoke(new Action(() => textBox.SelectAll()));
}

answered Nov 27 '18 at 14:34

mm8

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1

Thanks.. it's working. can you explain why we invoke the method inside the Dispatcher. Is there any specific reason for that? – Srinivasan Nov 27 '18 at 16:52
3

It's basically a timing issue. `Dispatcher.BeginInvoke` schedules the delegate that call `SelectAll()` to be executed when the UI thread is idle. – mm8 Nov 29 '18 at 15:52

score 17 · Answer 2 · edited May 02 '19 at 05:35

in App.xaml file

<Application.Resources>
    <Style TargetType="TextBox">
        <EventSetter Event="GotKeyboardFocus" Handler="TextBox_GotKeyboardFocus"/>
    </Style>
</Application.Resources>

in App.xaml.cs file

private void TextBox_GotKeyboardFocus(Object sender, KeyboardFocusChangedEventArgs e)
{
    TextBox tb = (TextBox)sender;
    tb.Dispatcher.BeginInvoke(new Action(() => tb.SelectAll()));
}

With this code you reach all TextBox in your Application

How to select all text in TextBox WPF when focused?

2 Answers2

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