Keypress navigation of an array of controls

[Tim Rowe]

I have a 2-d array of my own controls (derived from UserControl) on a panel in a Windows form. I would like the arrow keys to navigate in 2-dimensions, but the arrow keys get intercepted before I get to see them so I just get the default navigation (which goes through all of my controls as if they were in a single line. Can anyone tell me how to intercept the keystrokes and do my own handling? At the moment I'm overriding OnKeyPress on my own controls to try to catch the keypress, but the keypresses are not getting through. I've also tried adding

protected override bool IsInputChar(char charCode)
{
    if (charCode == (char)Keys.Up || charCode == (char)Keys.Down || charCode == (char)Keys.Left || charCode == (char)Keys.Right) return true;
    else return base.IsInputChar(charCode);
}
 

both to my controls and to the form, but it makes no difference (that code isn't seeing the keypresses either). I can only think it's being caught at the level of the panel that my controls are on, but I can't see a direct way of adding an IsInputChar handler to it. Do I have to subclass the panel, is there another way of doing it, or am I missing the point altogether?

[GaryTexmo]

Can you give us an idea of what your form might look like, and are the key presses intended to change the focus to the next control?

If the input is getting caught on the panel the controls are on, can you maybe handle it there?

Another way might be to try using a global keyboard hook. That will let you intercept the input at a lower level, so perhaps you can make use of that. Here's a code project link: http://www.codeproject.com/KB/cs/globalhook.aspx

[Tim Rowe]

It's a Japanese logic puzzle type of thing, so the game area is a rectangular array of cells in which various things happen. The game area is a panel, and the main form has other panels for status, buttons and so on. So I have an array of cells like:
1 2 3
4 5 6
7 8 9
(usually a lot bigger, and not numbered like that)
If I'm in cell 1, I want the down arrow to move me to cell 4, but at present it takes me to cell 2.

I'll have a look at the global keyboard hook, thanks.

[GaryTexmo]

I don't know the details of the user control you've got set up, but you might also try overriding the base class's KeyPressed event and not processing the base? I don't know if that would help... global keyboard hooks seem excessive for this application.

What's it doing right now with what have? Is it working and doing something else, or just not working at all?

[Tim Rowe]

What it was doing was the default navigation. For example, right or down navigated to the next control to the right, wrapping to the first control on the next row.

I've cracked it now. I had to handle my control's OnPreviewKeyDown event to set IsInputKey if it's a button I want, and handle my controls OnKeyDown (not OnKeyPress) event to do the actual handling, remembering to set the Handled flag.

Thanks.