Disabling keys on keyboard

Question

I am new to Objective-C, and I am looking to limit a user from switching from the alphabet portion of a normal keyboard to the numeric/punctuation side. This being said, I would

Answer 1

You actually can add and remove buttons of the default UIKeyboard

There's some recipes on the Internet like this: http://www.iphonedevsdk.com/forum/iphone-sdk-development/6573-howto-customize-uikeyboard.html and like this: http://www.iphonedevsdk.com/forum/iphone-sdk-development/6275-add-toolbar-top-keyboard.html

Those posts show you how to add a button, however the same principle can be used to remove.

Below I'll show you a compilation of one of the solutions:

//The UIWindow that contains the keyboard view - 
//It some situations it will be better to actually
//iterate through each window to figure out where the keyboard is, 
// but In my applications case
//I know that the second window has the keyboard so I just reference it directly
//
UIWindow* tempWindow = [[[UIApplication sharedApplication] windows] 
//                     objectAtIndex:1];

//Because we cant get access to the UIKeyboard throught the SDK we will 
// just use UIView. 
//UIKeyboard is a subclass of UIView anyways
UIView* keyboard;

//Iterate though each view inside of the selected Window
for(int i = 0; i < [tempWindow.subviews count]; i++)
{
    //Get a reference of the current view 
    keyboard = [tempWindow.subviews objectAtIndex:i];

    //Check to see if the className of the view we have 
    //referenced is "UIKeyboard" if so then we found
    //the keyboard view that we were looking for
    if([[keyboard description] hasPrefix:@"