// Call this method somewhere in your view controller setup code.

- (void)registerForKeyboardNotifications

{

    [[NSNotificationCenter defaultCenter] addObserver:self

            selector:@selector(keyboardWasShown:)

            name:UIKeyboardDidShowNotification object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self

            selector:@selector(keyboardWasHidden:)

            name:UIKeyboardDidHideNotification object:nil];

}

// Called when the UIKeyboardDidShowNotification is sent.

- (void)keyboardWasShown:(NSNotification*)aNotification

{

    if (keyboardShown)

        return;

    NSDictionary* info = [aNotification userInfo];

    // Get the size of the keyboard.

    NSValue* aValue = [info objectForKey:UIKeyboardBoundsUserInfoKey];

    CGSize keyboardSize = [aValue CGRectValue].size;

    // Resize the scroll view (which is the root view of the window)

    CGRect viewFrame = [scrollView frame];

    viewFrame.size.height -= keyboardSize.height;

    scrollView.frame = viewFrame;

    // Scroll the active text field into view.

    CGRect textFieldRect = [activeField frame];

    [scrollView scrollRectToVisible:textFieldRect animated:YES];

    keyboardShown = YES;

}

// Called when the UIKeyboardDidHideNotification is sent

- (void)keyboardWasHidden:(NSNotification*)aNotification

{

    NSDictionary* info = [aNotification userInfo];

    // Get the size of the keyboard.

    NSValue* aValue = [info objectForKey:UIKeyboardBoundsUserInfoKey];

    CGSize keyboardSize = [aValue CGRectValue].size;

    // Reset the height of the scroll view to its original value

    CGRect viewFrame = [scrollView frame];

    viewFrame.size.height += keyboardSize.height;

    scrollView.frame = viewFrame;

    keyboardShown = NO;

}

- (void)textFieldDidBeginEditing:(UITextField *)textField

{

    activeField = textField;

}

- (void)textFieldDidEndEditing:(UITextField *)textField

{

    activeField = nil;

}