Linda, Justin,

So this is cute, and now I'm really confused...

In my app, I have a form and at runtime I select a user control and place it
on the form. The specific user control I pick is in fact derived from a base
usercontrol that I created.

The KeyPreview property of the form itself is FALSE and the keydown event
handler is set up in the derived usercontrol. Neither the base control or the
form have any key related event handlers set up. The user control covers the
entire form which itself is maximized.

Now, what is weird is this.... I tried to create a sample, starting first
with just a default form, and I set a keydown event handler on it. I was
surprised when it did not detect the arrow keys at all. Going to the docs, I
worked out that I needed to set up a KeyPreview event handler where I could
check for the arrow keys and set e.IsInputKey to true. I did this, set a
breakpoint in the KeyDown handler, and lo and behold, it went off when I hit
the down arrow key and the test (e.KeyCode==Keys.Down) ran TRUE and
e.KeyCode.ToString was "Back | Space"

So, I removed all event handlers from my sample form, built an empty base
usercontrol and derived a usercontrol from it. Using the designer, I added a
KeyDown event handler. This matched by previous design. In the form, after
InitializeComponent(), I new'd my derived usercontrol and added it to the
form.

When I ran it and hit the down arrow key, my breakpoint in the KeyDown
handler DID NOT go off. I then added a PreviewKeyDown event handler and set
e.IsInputKey=true for the down arrow. When I reran the test, the downarrow
was trapped and matched properly in the keyDown event handler.

NOW, the control that made me post this problem in the first place DOES NOT
have a PreviewKeyDown event handler, nor does its base control, nor does the
form that the control is loaded into. Also, the form itself has
KeyPreview=false.

In this configuration, my KeyDown event handler DOES execute when the down
arrow is hit, BUT the keyCode is "RButton | ShiftKey", NOT "Back | Space"

When I went back and added a PreviewKeyDown event handler to my control and
with the following internal code:

           if (e.KeyCode == Keys.Down)
           {
               e.IsInputKey = true;
           }

my KeyDown event handler did successfully match e.KeyCode==Keys.Down

So, somehow my KeyDown event handler was getting invoked when I hit the down
arrow key (when it should not have been because I had no PreviewKeyDown
handler), and the KeyCode value was getting mangled.

Any thoughts??
I am running VS2005 but without SP1 (which made my entire VS environment
unusable and I had to completely remove and reinstall VS).

Thx
Marc