Question

I’ve got a control that derives from Forms.Control, it handles mouse events and paint events just fine, but I’m having a problem with key events. I need to handle Left arrow and Right arrow, but so far the Tab control that contains my class eats these.

How do I make this control selectable, focusable?

Answer 1

Here is a nice tutorial to make a focusable control. I just followed it to make sure it works. Also, added a keypress event to the control which works on condition that the control has focus.

http://en.csharp-online.net/Architecture_and_Design_of_Windows_Forms_Custom_Controls%E2%80%94Creating_a_Focusable_Control

Basically all I did was make an instance of my custom control, which inherits from Control. Then added KeyPress, Click, and Paint event. Key press was just a message:

void CustomControl1_KeyPress(object sender, KeyPressEventArgs e)
{
        MessageBox.Show(string.Format("You pressed {0}", e.KeyChar));
}

Click event just has:

this.Focus();
this.Invalidate();

The paint event I made like this, just so it was visible:

protected override void OnPaint(PaintEventArgs pe)
{
        if (ContainsFocus)
            pe.Graphics.FillRectangle(Brushes.Azure, this.ClientRectangle);
        else
            pe.Graphics.FillRectangle(Brushes.Red, this.ClientRectangle);
}

Then, in the main form, after making an instance called mycustomcontrol and adding the event handlers:

mycustomcontrol.Location = new Point(0, 0);
mycustomcontrol.Size = new Size(200, 200);
this.Controls.Add(mycustomcontrol);

The example is much neater than my five minute code, just wanted to be sure that it was possible to solve your problem in this way.

Hope that was helpful.