With the code below, the Left and Right arrow keys function as expected, but the up and down arrows are not recognized (stepping through it, the first two conditions are met where appropriate, but the second two never are):
private void textBox1_KeyDown(object sender, KeyEventArgs e) {
TextBox tb = (TextBox)sender;
if (e.KeyCode.Equals(Keys.Left)) {
SetFocusOneColumnBack(tb.Name);
e.Handled = true;
return;
}
if (e.KeyCode.Equals(Keys.Right)) {
SetFocusOneColumnForward(tb.Name);
e.Handled = true;
return;
}
if (e.KeyCode.Equals(Keys.Up)) {
SetFocusOneRowUp(tb.Name);
e.Handled = true;
return;
}
if (e.KeyCode.Equals(Keys.Down)) {
SetFocusOneRowDown(tb.Name);
e.Handled = true;
return;
}
}
Why would this be, and how can I fix it?
UPDATE
Here's what I see when I hover over e.Keycode while stepping through. If I pressed
- ...Left arrow key, I see:
e.KeyCode = "LButton | MButton | Space"
- ...Right arrow key, I see:
e.KeyCode = "LButton | RButton | MButton | Space"
- ...Up arrow key, I see:
e.KeyCode = "RButton | MButton | Space"
- ...Down arrow key, I see:
e.KeyCode = "Backspace | Space"
This has got me baffled (what it's showing me), but on keyleft and keyright, my code is entered - it never is for keyup and keydown, no matter how hard I clench my teeth.
You can use this code:
Windows captures certain keys for UI navigation before they every get sent to your form. If you want to override this behavior you need to overload the
IsInputKey
method (and subclass the text field):I find that using the PreviewKeyDown does work (I had to remove the "e.Handled = true" code, as it doesn't apply in the PreviewKeyDown event):
So, three different events were needed to handle the various keys I was looking for: KeyPress for regular characters, KeyDown for non-characters (left and right arrow keys) and this one (PreviewKeyDown) for the up and down arrow keys.
Well too late for the party but if anyone is interested, use
e.KeyValue
instead, as an example,e.KeyValue
for left arrow key is37
and for right arrow key39
and so on.