PreviewKeyDown

This fixes a problem with keyboard input on DataGridView. If the user focuses a cell and presses enter, the selection might not work properly.

By using PreviewKeyDown, we can correct an issue with keyboard navigation. If you have a problem with selecting moving, consider PreviewKeyDown.

Example

Let us closely examine the problem using KeyCode and KeyDown. When the enter key was detected, my dialog would close and I would see the appropriate response.

void dataGridView1_KeyDown(object sender, KeyEventArgs e)
{
    //
    // Set the key down event has handled.
    // We call our function ProceedOpen in the PreviewKeyDown event instead.
    //
    if (e.KeyCode == Keys.Enter)
    {
        e.Handled = true;
    }
}

PreviewKeyDown example

Here we stop the KeyDown from moving the selection. However, before the runtime raises the KeyDown event, it will raise PreviewKeyDown.

void dataGridView1_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
    //
    // If the key pressed is enter, then call ProceedOpen.
    //
    if (e.KeyCode == Keys.Enter)
    {
        ProceedOpen();
    }
}

A summary

PreviewKeyDown can help your keyboard navigation techniques work well. PreviewKeyDown can solve selection moved problems in Windows Forms.