Question

I do not want an external keyboard to be allowed in my app. I realize this is an edge case but I do not like how the keyboard will not be shown when an external keyboard is used. Especially because I have a custom view above the keyboard that will now be shown at the bottom of the screen. Also, I have textfields that should only require numbers (phonenumber for example). Instead of checking input, I would rather just show the numbers keyboard. Obviously this can’t happen with external keyboard.

I saw a post here: How to detect external keyboard connectification in objective-c?

but that’s not enough to just detect it…I want to disable!

Thanks,

-Adam

Answer 1

Here are two things you can do to circumvent this problem:

You can force the keyboard to appear even when there is an external keyboard present.

You can validate text input using the UITextField delegate method

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string

For example, to allow only numbers to be entered, you can do:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

    NSCharacterSet *myCharSet = [NSCharacterSet characterSetWithCharactersInString:@"0123456789"];

    if ([[string stringByTrimmingCharactersInSet:myCharSet] length]) {
        return YES;
    } else {
        return NO;
    }
}