UIMenuController does not show after changing the view controller

Question

I have 2 viewControllers and in first one I'm using tapRecognizer to press and hold in order to show a UImenucontroller to copy a string. The tap is used for selecting the title on navigation bar, and it shows a UImenucontroller with copy item on it.

It works for the first time, but when user switch to another view controller and come back to the first view controller again, the menu does not show any more.

-(void)viewDidLoad{
    [super viewDidLoad];
    UIView *viewWithTitleLabel = self.navigationController.navigationBar.subviews[1];
    viewWithTitleLabel.userInteractionEnabled = YES;

    UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(topBarTitleTap:)];
    [viewWithTitleLabel addGestureRecognizer:longPress];
}

-(void)topBarTitleTap:(UILongPressGestureRecognizer *)gestureRecognizer
{
    if ([gestureRecognizer state] == UIGestureRecognizerStateBegan) {
        UIMenuController *menuController = [UIMenuController sharedMenuController];
        [menuController setTargetRect:CGRectMake(CGRectGetMidX([self.view bounds]), -12.0, 0.0f, 0.0f) inView:self.view];
        [menuController setMenuVisible:YES animated:YES];
    }
}

- (void) copy:(id) sender {
    // called when copy clicked in tab bar title
    NSString *copyStringverse = self.navigationItem.title;
    UIPasteboard *pasteboard = [UIPasteboard generalPasteboard];
    [pasteboard setString:copyStringverse];
}

- (BOOL) canBecomeFirstResponder {
    return YES;
}

Answer 1

Add [self becomeFirstResponder]; before pop UIMenuController For example you can change your code as follow

-(void)topBarTitleTap:(UILongPressGestureRecognizer *)gestureRecognizer
{
    [self becomeFirstResponder];
    if ([gestureRecognizer state] == UIGestureRecognizerStateBegan) {
        UIMenuController *menuController = [UIMenuController sharedMenuController];
        [menuController setTargetRect:CGRectMake(CGRectGetMidX([self.view bounds]), -12.0, 0.0f,     0.0f) inView:self.view];
        [menuController setMenuVisible:YES animated:YES];
    }
}

And don't forget to implement

-(BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
    //Customize your action if statement here
    return YES;
}

For your viewcontroller