UITextfield Input to Upper Case forcefully -- ios sdk

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range

replacementString:(NSString *)string {

    // Check if the added string contains lowercase characters.

    // If so, those characters are replaced by uppercase characters.

    // But this has the effect of losing the editing point

    // (only when trying to edit with lowercase characters),

    // because the text of the UITextField is modified.

    // That is why we only replace the text when this is really needed.

    NSRange lowercaseCharRange;

    lowercaseCharRange = [string rangeOfCharacterFromSet:[NSCharacterSet lowercaseLetterCharacterSet]];

    if (lowercaseCharRange.location != NSNotFound) {

        textField.text = [textField.text stringByReplacingCharactersInRange:range

                                                                 withString:[string uppercaseString]];

        return NO;

    }

    return YES;

}