How to get keypressed, keydown events from DataGridView data cells

Question

I need to receive the key press events during cell editing in DataGridView control.

From what I have found on the net the DataGridView is designed to pass all key events from DataGridView to the cell editing control and you cannot get these events easily.

I found this piece of code that traps those events for DataGrid control, but that does not work for DataGridView.

Answer 1

Try this:

class KeyPressAwareDataGridView : DataGridView
{
    protected override void OnControlAdded(ControlEventArgs e)
    {
        SubscribeEvents(e.Control);
        base.OnControlAdded(e);
    }

    protected override void OnControlRemoved(ControlEventArgs e)
    {
        UnsubscribeEvents(e.Control);
        base.OnControlRemoved(e);
    }

    private void SubscribeEvents(Control control)
    { 
        control.KeyPress += new KeyPressEventHandler(control_KeyPress);
        control.ControlAdded += new ControlEventHandler(control_ControlAdded);
        control.ControlRemoved += new ControlEventHandler(control_ControlRemoved);

        foreach (Control innerControl in control.Controls)
        {
            SubscribeEvents(innerControl);
        }
    }

    private void UnsubscribeEvents(Control control)
    {
        control.KeyPress -= new KeyPressEventHandler(control_KeyPress);
        control.ControlAdded -= new ControlEventHandler(control_ControlAdded);
        control.ControlRemoved -= new ControlEventHandler(control_ControlRemoved);

        foreach (Control innerControl in control.Controls)
        {
            UnsubscribeEvents(innerControl);
        }
    }

    private void control_ControlAdded(object sender, ControlEventArgs e)
    {
        SubscribeEvents(e.Control);
    }

    private void control_ControlRemoved(object sender, ControlEventArgs e)
    {
        UnsubscribeEvents(e.Control);
    }

    private void control_KeyPress(object sender, KeyPressEventArgs e)
    {
        // Apply your logic here whether this is the key pressed event you need.
        // (e.g. "if(SelectedCells != null)")
        MessageBox.Show(e.KeyChar.ToString());
    }
}

Answer 2

Finally figured out. There are two parts of this puzzle - getting keys from cell editing control and getting keys from the DataGridView itself. Here's my code. To use it, you just need to subscribe to the custom event: keyPressHook.

class KeyPressAwareDataGridView : DataGridView
{

    protected override void OnControlAdded(ControlEventArgs e)
    {
        this.subscribeEvents(e.Control);
        base.OnControlAdded(e);
    }

    protected override void OnControlRemoved(ControlEventArgs e)
    {
        this.unsubscribeEvents(e.Control);
        base.OnControlRemoved(e);
    }

    protected override bool ProcessDataGridViewKey(KeyEventArgs e)
    {
        bool procesedInternally = false;

        if (this.keyPressHook != null)
        {
            this.keyPressHook(this, e);
            procesedInternally = e.SuppressKeyPress;
        }

        if (procesedInternally)
        {
            return true;
        }
        else
        {
            return base.ProcessDataGridViewKey(e);
        }
    }


    private void subscribeEvents(Control control)
    {
        control.KeyDown += new KeyEventHandler(this.control_KeyDown);
        control.ControlAdded += new ControlEventHandler(this.control_ControlAdded);
        control.ControlRemoved += new ControlEventHandler(this.control_ControlRemoved);

        foreach (Control innerControl in control.Controls)
        {
            this.subscribeEvents(innerControl);
        }
    }

    private void unsubscribeEvents(Control control)
    {
        control.KeyDown -= new KeyEventHandler(this.control_KeyDown);
        control.ControlAdded -= new ControlEventHandler(this.control_ControlAdded);
        control.ControlRemoved -= new ControlEventHandler(this.control_ControlRemoved);

        foreach (Control innerControl in control.Controls)
        {
            this.unsubscribeEvents(innerControl);
        }
    }

    private void control_ControlAdded(object sender, ControlEventArgs e)
    {
        this.subscribeEvents(e.Control);
    }

    private void control_ControlRemoved(object sender, ControlEventArgs e)
    {
        this.unsubscribeEvents(e.Control);
    }

    private void control_KeyDown(object sender, KeyEventArgs e)
    {
        if (this.keyPressHook != null)
        {
            this.keyPressHook(this, e);
        }
    }

    public event KeyEventHandler keyPressHook;

}