CODEWITHSUNDEEP
c#wpftextblock
Victor .S
Victor .S

Reputation: 37

How do I change a TextBlock Text during Buton Click?

I´d like to change the text of a TextBlock during a Button_Click in WPF. I tried this but it did not work:

private void Button_Click(object sender, RoutedEventArgs e)
{
    myTextBlock.Text = "Status: Not ready";

    //Do Something

    myTextBlock.Text = "Status: Ready";

}

Upvotes: 2

Views: 1721

Answers (3)

Quentin Couderc
Quentin Couderc

Reputation: 86

To avoid writing all the processing in the thread i do it :

        private async void Button_Click(object sender, RoutedEventArgs e)
        {
            
             myTextBlock.Text = "Status: Not ready";
             await Task.Run(() =>
             {
                 Thread.Sleep(1000);
             }).ConfigureAwait(true);

             //Do your processing
             Treatment();

             myTextBlock.Text = "Status: Ready";
        }

Upvotes: 0

mm8
mm8

Reputation: 169190

You need to replace the comment //Do Something with some code that actually does something on another thread. If you don't, you will never get the chance to see the "Status: Not ready" message as the Text property will be set to "Status: Ready" almost immediately after you have clicked the Button.

Try this:

private async void Button_Click(object sender, RoutedEventArgs e)
{
    myTextBlock.Text = "Status: Not ready";

    await Task.Delay(3000); //wait asynchronously for 3 seconds..

    myTextBlock.Text = "Status: Ready";

}

After you have confirmed that this works as expected you probably want to start a task that does something meaningful as suggested by @Fruchtzwerg. ConfigureAwait(true) is superfluous here though:

await Task.Run(() =>
{
    //Do something
});

Upvotes: 0

Fruchtzwerg
Fruchtzwerg

Reputation: 11389

Button_Click is called out of the UI thread. This means executed code will block updating your UI. A simple solution is to use async and await and a new thread to run your blocking action. This allows the UI thread to update the UI during the blocking action.

private async void Button_Click(object sender, RoutedEventArgs e)
{
    myTextBlock.Text = "Status: Not ready";

    await Task.Run(() =>
    {
        //Your code here
    }).ConfigureAwait(true);

    myTextBlock.Text = "Status: Ready";
}

Note that you need to add ConfigureAwait(true) to use the UI thread again to update the text the second time.

Upvotes: 3

Related Questions