Windows Dialog does not handle keydown event Enter or Return

Question

Why does dialogresult work on button click but not on keydown? I'm working on Desktop application.

Rigobert GANDE · Answer

I'm working on a WPF/.NET 10 project I have a message (information) box with a single OK button that sets isDefault = "true". Normally, when the message box appears and the user presses the Enter key, it should close in response to the associated Click() event. private void okButton_Click(object sender, RoutedEventArgs e) { this.Dispatcher.BeginInvoke(new Action(async () => { DialogResult = true; }), DispatcherPriority.ApplicationIdle); } The click works without the window closing correctly. But when I press the Enter key, the program crashes for no reason, without an error message.

Raghunath Bhukan · Answer

DialogResult works automatically on button clicks because the framework wires it up for you. KeyDown does not trigger that wiring. Why DialogResult works on a Button click In WinForms: buttonOk.DialogResult = DialogResult.OK; When a button with DialogResult is clicked: WinForms sets the form’s DialogResult WinForms automatically closes the dialog ShowDialog() returns that result This behavior is built into the Button control . Why it does NOT work in KeyDown When you handle a key press: private void Form_KeyDown(object sender, KeyEventArgs e) { if (e.KeyCode == Keys.Enter) { this.DialogResult = DialogResult.OK; } } What happens? The DialogResult does get set The form does NOT automatically close ShowDialog() does not return yet Because: Setting DialogResult manually does not close the form unless the form is being closed by a dialog-aware control (like a Button). The correct way to handle DialogResult in KeyDown Option 1: Set DialogResult and close the form private void Form_KeyDown(object sender, KeyEventArgs e) { if (e.KeyCode == Keys.Enter) { this.DialogResult = DialogResult.OK; this.Close(); } } This mimics what the Button does internally. Option 2: Use AcceptButton / CancelButton (BEST PRACTICE) Instead of handling KeyDown manually: this.AcceptButton = buttonOk; this.CancelButton = buttonCancel; Now: Enter triggers buttonOk Esc triggers buttonCancel DialogResult works automatically Cleaner, more accessible, Standard Windows behavior Important KeyDown Details (Another common pitfall) If your KeyDown never fires , check these: 1. Enable KeyPreview this.KeyPreview = true; Without this, focused controls (TextBox, etc.) eat the key events. 2. Use the correct event KeyDown ? good for Enter/Esc KeyPress ? character input PreviewKeyDown ? for special keys in some controls Summary Scenario Why it works / doesn’t Button click WinForms auto-handles DialogResult + Close KeyDown DialogResult set, but no auto close Fix Call Close() or use AcceptButton Best practice AcceptButton / CancelButton Recommendation If this is a dialog: Do NOT handle Enter/Esc manually. Use AcceptButton and CancelButton .

Sam Hobbs · Answer

I need more information. Where does it not work? What button? What event is being handled?

Windows Dialog does not handle keydown event Enter or Return

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