I'm trying to write an event driven keyboard component, but it doesn't seem to check all the keys. I didn't want to type them all in, so I used this loop:

            for (int i = (int)Keys.A; i <= (int)Keys.Zoom; i++)
                checkKey((Keys)i, newState);

It works for most keys, but I noticed Escape, Space, and Enter are never caught. Any ideas? 

You can use reflection here to your advantage. For my EBIS (Event Based Input Service/System) I loop through the enum itself and add the necessary keys to a collection, leaving out Alt, Control and Shift since they are modifier keys and are checked and passed along as simple booleans.

To loop through all the values of an enum do the following:

for ( int i = 0; i < Enum.GetValues( typeof( Keys ) ).Length; i++ )
{
       Keys key =  (Keys)Enum.GetValues( typeof( Keys ) ).GetValue(i); 

       checkKey( key, newState );
}

To explain, the Enum.GetValues( typeof( Keys ) ).Length,

Enum.GetValues( ) returns an System.Array of the enum's members so wet give it a typeof(Keys) and then grab the length of that array to know how far to loop through.

Keys key = ( (Keys[])Enum.GetValues( typeof( Keys ) ) )[i] is more complicated but what we're doing here is grabbing the System.Array and using GetValue() to grab the object at the index i. Then we cast the object to a Keys enum and we've got our key!

You could also do:

Keys key = ( (Keys[])Enum.GetValues( typeof( Keys ) ) )[i];
 

Keys key =  (Keys)Enum.GetValues( typeof( Keys ) ).GetValue(i);

Now, this example is awsome, I got to say, this is exactly what I've been looking for too, for a keyboard handler/manager/thing I've been working on too. But, this line screams of inefficency to me.  Now, I know this is C# and I'm used to C/C++ so, really it might be a minor thing.  But, Would creating a new array to store the values and then using that, be a smarter method of doing this for speed/performance reasons?  Seems to me, a lot of work for every value in Keys is being done when it can be done once, heck once at the start up of the application, and used then instead.   Or does it not matter with C#. it's smart enough to optimize for this sort of thing.

  Tony
 

Well, that was exactly what I was thinking even.  I too was looking to design a simple class that's purpose is to keep track of how long each key has been pressed and if specific conditions are meet, flag the key as 'pressed' again so that anything monitoring specific key presses or generally, looking to get the last key pressed, would generally work out smoothly.

 I figured there are a few things I need to keep track of.  The users Repeat Delay and Repeat Rate (System settings or perhaps just fudge with local values), the time a key was pressed, the length of time it's been pressed, and the last time it was 'used'.  This way, I can properly simulate a key press, allowing for a delay and then repeat action when appropriate.

 
Functioning like this might be best for situations like, navigating a 2D map, or handling text input.  Say, the user entering a name or sending a text message to another player.

Seems to me, functionality like this would be somewhat nice and not that difficult to duplicate. 

Sentack 

TehOneAndOnly:

Krisc... sharing code??? Never!

ha. I am releasing the next GUI video soon, and it includes most, if not all of this.

Ebi Class: http://xna.multigan.com/pastebin/?page=view&id=1175173398

Ebi Service Interface and Additional Stuff: http://xna.multigan.com/pastebin/?page=view&id=1175173434