UIMenuController具有零帧

Question

我真的经历了与此主题相关的所有其他问题。但到目前为止，没有人帮助我。

我想在UIMenuController上显示UIView。因此，我将UIView子类化，并且已经实现了所有必需的方法。 在UIViewController我实例化UIGestureRecognizer并将其添加到自定义UIView。这很好用。我也可以处理长按手势。只是UIMenuController 不会出现！

@interface CopyableView : UIView
@end

@implementation CopyableView

- (BOOL)canBecomeFirstResponder
{
    NSLog(@"_CAN BECOME 1. RESPONDER_");
    return YES;
}

- (BOOL)canPerformAction:(SEL)action
              withSender:(id)sender
{
    NSLog(@"_CAN PERFORM ACTION_");
    return (action == @selector(copy:));
}

- (void)copy:(id)sender
{
    NSLog(@"_COPY_");
}

@end


@interface InfoViewController : UIViewController

@property (nonatomic, weak) IBOutlet CopyableView *myView;

@end

@implementation InfoViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    [self.myView addGestureRecognizer:[[UILongPressGestureRecognizer alloc] initWithTarget:self
                                                                                    action:@selector(handleLongPressGesture:)]];
}

- (void)handleLongPressGesture:(UILongPressGestureRecognizer *)recognizer
{
    if (recognizer.state == UIGestureRecognizerStateBegan)
    {
        NSLog(@"__ %i __", [UIMenuController sharedMenuController].menuVisible);

        [self.myView becomeFirstResponder];

        UIMenuItem *item = [[UIMenuItem alloc] initWithTitle:@"Copy"
                                                      action:@selector(copy:)];
        [[UIMenuController sharedMenuController] setMenuItems:@[item]];
        [[UIMenuController sharedMenuController] setTargetRect:CGRectMake(33, 33, 33, 33)
                                                        inView:self.myView];
        [[UIMenuController sharedMenuController] setMenuVisible:YES
                                                       animated:NO];

        NSLog(@"__ %i __", [UIMenuController sharedMenuController].menuVisible);
        NSLog(@"#### %@ ####", NSStringFromCGRect([UIMenuController sharedMenuController].menuFrame));
    }
}

检查[UIMenuController sharedMenuController].menuVisible会在方法结束时返回true。所以事情似乎有效。我仍然没有看到任何事情发生。 UIMenuController的框架是{{0, 0}, {0, 0}}，我无法理解。