可见窗体后Button.Text更改

Question

I have a button that loads a Form, as it gets lots of data from a database and takes a few seconds, I want to advise the user to wait.

When I click the button the button text does not change.

This is the button Click code I am using:

private void btnItemConfigForm_Click(object sender, EventArgs e)
            {
                var itemConfigBtnText = btnItemConfigForm.Text;
                btnItemConfigForm.Text = "Waiting...";

                ItemConfigForm form = new ItemConfigForm();
                form.Show();

                if (form.Created)
                {
                    btnItemConfigForm.Text = itemConfigBtnText;
                }
            }

If I Comment out

if (form.Created)
{
    btnItemConfigForm.Text = itemConfigBtnText;
}

Then the button text changes to waiting after the new form window is visible.

What am I missing to get the button text to change before the form window is visible.

Answer 1

the simple solution is to add this row:

btnItemConfigForm.Refresh();

after this row

btnItemConfigForm.Text = "Waiting...";

Otherwise the text of the button will be changed only when the function ends, this function will redraw the form display!

Ps If you want the form will not be blocked - you can use in asynchronic running to the function "Show" (or New) then you will need Event to notify the first form when the form will be loaded

sorry for my English... :)

Answer 2

Added

  btnItemConfigForm.Update();

under

var itemConfigBtnText = btnItemConfigForm.Text;
btnItemConfigForm.Text = "Waiting...";

This updates the button Control before moving on to initialising and showing the form.