Question

For a textbox, I want to display a tooltip immediatly when the focus is in on the textbox, and stay there for the duration of the focus – not just when the mouse hovers over the textbox.

How can I do that?

Answer 1

The Enter and Leave events are probably useful here, and show it with a duration of 0 to keep it there.

private ToolTip tt;

private void textBox1_Enter(object sender, EventArgs e) {
  tt = new ToolTip();
  tt.InitialDelay = 0;
  tt.IsBalloon = true;
  tt.Show(string.Empty, textBox1);
  tt.Show("I need help", textBox1, 0);
}

private void textBox1_Leave(object sender, EventArgs e) {
  tt.Dispose();
}

Note: Calling the Show(...) method twice like in my example will force the “pointer” to point correctly to the control.