Question

I have been trying to write a small app with its own option windows. When I try to launch the window I can never seem to set focus on the new form. This is not a mdi form, but merely a new form that I create when a user selects an option from the menu. It should be noted that Form.Show is return false, which means that the new form is never receiving focus.

I have tried multiple methods for loading the form and all have failed:

From Calling Form:

ServerForm SF = new ServerForm(ref DataLoader, false);
SF.Show();
SF.Focus();
// Fails

Inside the form itself:

this.Show();
this.BringToFront();
this.Activate();
this.TopMost = true;
// Fails

Setting Form to selectable:

this.SetStyle(System.Windows.Forms.ControlStyles.Selectable, true);
...
ServerForm SF = new ServerForm(ref DataLoader, false);
SF.Show();
SF.Focus();
// Fails

Using Old API:

[System.Runtime.InteropServices.DllImport("user32.dll")]
private static extern int ShowWindow(IntPtr handle, int nCmdShow);    
ServerForm SF = new ServerForm(ref DataLoader, false);
ShowWindow(SF.Handle, 3);
SF.Show();
SF.Focus();
// Fails

Passing in Parent

ServerForm SF = new ServerForm(ref DataLoader, false);
SF.Show(this);
SF.Focus();
// Fails

In all of these cases the form will show up, but the form that spawned still will have focus over the new form. This happens even when I disable the old form before I create the new form.

Any suggestions?

Answer 1

This seems to work. First I create the new form:

private void changeDefaultServerToolStripMenuItem_Click(object sender, EventArgs e)
{
    this.Enabled = false;
    ServerForm SF = new ServerForm(ref DataLoader, true);
}

Then in the constructor for the new form I do the following:

this.BringToFront();
this.CenterToParent();
this.TopMost = true;
this.ShowDialog();

Apparently there is some sort of behind the scene difference between Form.Show and Form.ShowDialog. Not quites sure what it is, I can only think it has to do with setting the active parent somehow. Adding code after the call to construct the function does not seem to give back focus to the parent form. Which it shouldn’t.