UIMenuController在Cell内部无法显示的解决办法（iOS9.2）

@implementation CollectionViewCell //继承自UICollectionViewCell  UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPress:)]; longPress.minimumPressDuration = 1; [self addGestureRecognizer:longPress];//添加长按手势//实现长按方法- (void)longPress:(UILongPressGestureRecognizer *)gesture{ switch (gesture.state) { case UIGestureRecognizerStateBegan: {  [self becomeFirstResponder];<span style="color: rgb(255, 0, 0);">//必须有！</span>  UIMenuController *menu = [UIMenuController sharedMenuController];  UIMenuItem *item1 = [[UIMenuItem alloc] initWithTitle:@"保存" action:@selector(savePic)];  menu.menuItems = [NSArray arrayWithObject:item1];  [menu setTargetRect:self.scView.frame inView:self.scView.superview];  [menu setMenuVisible:YES animated:YES]; }  break; default:  break; }}<span style="color: rgb(0, 128, 0);">//必须实现。注意不是- (BOOL)becomeFirstResponder方法</span>- (BOOL)canBecomeFirstResponder{ return YES;}