how to handle key events in iphone

You cant directly code for keyboad;s key and there is no mouse in case of device.

you can make your logics for different kind of charectersets or you can make your logics in textField delgate methods or Textview Delegates method

textView delegate

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text 

textField delegate

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

You can also use Notification for textField and Textview.

For TextField use this

call this register method in viewDidLoad

-(void)registerForTextFieldNotifications { NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter]; [notificationCenter addObserver:self selector:@selector (handle_TextFieldTextChanged:) name:UITextFieldTextDidChangeNotification object:self.textField]; } - (void) handle_TextFieldTextChanged:(id)notification { if([iSinAppObj.passCodeString isEqualToString:lockTextField.text]) { //code here } } 

and for text view you need to change only event name like this

[notificationCenter addObserver:self selector:@selector (handle_TextFieldTextChanged:) name:UITextViewTextDidChangeNotification object:self.textField];