モダルビューアからキーボードを非表示にする方法

- (IBAction)close:(id)sender {

    [textField resignFirstResponder];

    @try

    {

        Class UIKeyboardImpl = NSClassFromString(@"UIKeyboardImpl");

        id activeInstance = [UIKeyboardImpl performSelector:@selector(activeInstance)];

        [activeInstance performSelector:@selector(dismissKeyboard)];

    }

    @catch (NSException *exception)

    {

        NSLog(@"%@", exception);

    }

}