How to defocus a button when barcode scanner sent data ending with newline

Question

I am writing a C# barcode application. I have a EAN-13 regex to detect barcodes in \"Form1_KeyPress\" function. I have no mechanism to detect where the input comes from. Her

Answer 1

You can't capture the Enter key in the form's keystroke events because it is handled by the button.

If you add:

private void button_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
    if (e.KeyCode == Keys.Enter)
    {
        e.IsInputKey = true;
    }
}

to a button then the Enter key won't cause the button to be clicked, and you will see a Form_KeyDown event for it.

You don't want to add this to every button, so create a simple UserControl which is just a button with this code added.

Update

This doesn't work for the space bar. If you set form.KeyPreview = true and add:

private void form_KeyDown(object sender, KeyEventArgs e)
{
    if (e.KeyCode == Keys.Space)
    {
        e.Handled = true;
    }
}

then the space bar won't press the button but it will still work in text boxes.

I don't know why Space and Enter behave differently.