Question

I’m trying to bind a Textbox.Text to Form.Text (which sets the title of the form).
The binding itself works. But, the title isn’t updated until I move the entire form.

How can I achieve Form.Text being updated without moving the form? I’d like Form.Text being updated directly when I type something in the Textbox.

Edit; I set the title of the Form in a TextChanged event which is fired by a ToolStripTextbox:

public partial class ProjectForm : Form
{
   public ProjectForm()
   {
       // my code contains all sorts of code here, 
       // but nothing that has something to do with the text.
   }
}

private void projectName_TextChanged_1(object sender, EventArgs e)
{
    this.Text = projectName.TextBox.Text;
}

And the Databinding version:

public partial class ProjectForm : Form
{
   public ProjectForm()
   {
       this.projectName.TextBox.DataBindings.Add("Text", this, "Text", true, DataSourceUpdateMode.OnValidation);
   }
}

Edit 2: I see I forgot to mention something. Don’t know if it adds anything, but my apllication is a MDI application. The part of the title that changes is:

ApplicationName [THIS CHANGES, BUT ONLY AFTER MOVING/RESIZING]

Answer 1

Classic problem, you’re not updating the existing form’s Text property but a new one that is not visible. Call the Show() method after you change the Text.

Source

You can also try invalidating your form in the TextChanged event so it will force a re-paint.

Edit 1: This StackOverflow question may provide an answer for you since you are a MDI application

Edit 2: It could be that this operation is not thread-safe and therefore the UI thread is blocking. Therefore, you need to invoke another function in order to cause it to update. I had a similar problem with StatusBar Labels a while back. Here is some example code if you do not know how to use delegates:

public delegate void updateFormTextD(string text);

private void formText(string text)
{
     this.Text = text;
}

private void updateFormText(string text)
{
     Invoke(new updateFormTextD(formText), text);
}