Question

I have a .net winforms application, where multiple forms are displayed at one time. One form is routinley disabled (this.enabled = false;). During this time, the form creates and shows a custom modal dialog. When the dialog is closed, the original form, the one that is disabled, loses focus. I removed the code that set the form as disabled, and when I tested that, the form kept the focus after returning from the dialog. Is there any way to have a disabled form open up a modal custom dialog, and then stay focused and on top of the other forms when the dialog is closed?

Answer 1

No. The Windows manager must pick another window to give the focus to when the dialog closes. When your app has no enabled windows left, it must pick a window of another application. Which is likely to push your app’s windows into the background.

A possible workaround is to quickly enable the window before the dialog closes and disable it again afterwards. Like this:

using (var dlg = new Form2()) {
    dlg.FormClosing += new FormClosingEventHandler((s, ea) => {
        if (!ea.Cancel) this.Enabled = true; 
    });
    if (dlg.ShowDialog() == DialogResult.OK) {
        // etc...
    }
    this.Enabled = false;
}

But do note that this is in general a usability problem. Once the user switches to another application, she can’t switch back to yours again.