UILongPressGestureRecognizer不適用於所有UIButton

Question

我有一個問題，我擔心有一個簡單的解決方案。 每次調用'createNewSetInDB：'方法時，都會創建一個新的UIButton *，為用戶按下按鈕時分配一個目標，並為用戶長按該按鈕時分配一個UILongPressGesture *。

當用戶點擊這些按鈕之一時，將正確調用'openSet：'方法。 僅為創建的LAST UIButton *調用'showHandles：'長按方法。 因此，如果“ createNewSetInDB：”方法被調用了4次並因此創建了4個UIButton，則前三個不處理UILongPressGesture。 第四個UIButton可以。

有任何想法嗎？

UILongPressGestureRecognizer *showHandlesLongPress;

- (void)viewDidLoad

{
    showHandlesLongPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(showHandles:)];
    showHandlesLongPress.minimumPressDuration = .5;
}

- (void)createNewSetInDB:(BOOL)doWeAddItToTheDatabase
{
    UIButton *newSet = [[UIButton alloc]initWithFrame:
                                   CGRectMake((sliderMusic.frame.origin.x + imgWhiteLine.frame.size.width / 2) + (_musicPlayer.currentPlaybackTime * 10),
                                                                 6,
                                                                 35,
                                                                 25)];

    [newSet addTarget:self action:@selector(openSet:) forControlEvents:UIControlEventTouchUpInside];
    [newSet setTitleColor:[MobileMarcherVariables sharedVariableInstance].systemColor forState:UIControlStateNormal];
    [newSet.layer setBorderColor:[[MobileMarcherVariables sharedVariableInstance].systemColor CGColor]];
    [newSet.layer setBorderWidth:1];
    [newSet.titleLabel setFont:[UIFont systemFontOfSize:15]];
    [newSet setTitle:[NSString stringWithFormat:@"%i",totalNumberOfSets] forState:UIControlStateNormal];
    [scrollviewMusic addSubview:newSet];
    [arrayofSetButtons addObject:newSet];
    [newSet addGestureRecognizer:showHandlesLongPress];

    if (doWeAddItToTheDatabase) [[NSNotificationCenter defaultCenter] postNotification:newSetNotification];

}


- (void)showHandles:(UILongPressGestureRecognizer*)gesture
{
    if (gesture.state == UIGestureRecognizerStateBegan)
    {
        NSLog(@"long press");
        for (UIButton *but in arrayofSetButtons)
        {
            if (but.tag != gesture.view.tag)
            {
                but.alpha = .5;
            }
        }

        [scrollviewMusic bringSubviewToFront:lefthandle];
        [scrollviewMusic bringSubviewToFront:righthandle];
        lefthandle.hidden = NO;
        righthandle.hidden = NO;

        lefthandle.frame = CGRectMake(gesture.view.frame.origin.x - 1,
                                      gesture.view.frame.origin.y - gesture.view.frame.size.height,
                                      2, 50);
        righthandle.frame = CGRectMake((gesture.view.frame.origin.x - 1) + gesture.view.frame.size.width,
                                       gesture.view.frame.origin.y - gesture.view.frame.size.height,
                                       2, 50);
    }
}

Answer 1

手勢識別器一次只能附加到一個視圖。 您僅創建一個手勢識別器。 每次創建按鈕時，都會將現有的手勢識別器附加到新按鈕上，從而將其從上一個按鈕中刪除。

為每個新按鈕創建一個新的手勢識別器。

- (void)createNewSetInDB:(BOOL)doWeAddItToTheDatabase
{
    UIButton *newSet = [[UIButton alloc]initWithFrame:
                                   CGRectMake((sliderMusic.frame.origin.x + imgWhiteLine.frame.size.width / 2) + (_musicPlayer.currentPlaybackTime * 10),
                                                                 6,
                                                                 35,
                                                                 25)];

    [newSet addTarget:self action:@selector(openSet:) forControlEvents:UIControlEventTouchUpInside];
    [newSet setTitleColor:[MobileMarcherVariables sharedVariableInstance].systemColor forState:UIControlStateNormal];
    [newSet.layer setBorderColor:[[MobileMarcherVariables sharedVariableInstance].systemColor CGColor]];
    [newSet.layer setBorderWidth:1];
    [newSet.titleLabel setFont:[UIFont systemFontOfSize:15]];
    [newSet setTitle:[NSString stringWithFormat:@"%i",totalNumberOfSets] forState:UIControlStateNormal];
    [scrollviewMusic addSubview:newSet];
    [arrayofSetButtons addObject:newSet];

    UILongPressGestureRecognizer *showHandlesLongPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(showHandles:)];
    showHandlesLongPress.minimumPressDuration = .5;
    [newSet addGestureRecognizer:showHandlesLongPress];

    if (doWeAddItToTheDatabase) [[NSNotificationCenter defaultCenter] postNotification:newSetNotification];

}

Answer 2

您必須為每個UIButton分配一個UILongPressGestureRecognizer 。 它們都可以指向相同的方法。

- (void)createNewSetInDB:(BOOL)doWeAddItToTheDatabase
{
    UIButton *newSet = [[UIButton alloc]initWithFrame:
                        CGRectMake((sliderMusic.frame.origin.x + imgWhiteLine.frame.size.width / 2) + (_musicPlayer.currentPlaybackTime * 10),
                                   6,
                                   35,
                                   25)];

    [newSet addTarget:self action:@selector(openSet:) forControlEvents:UIControlEventTouchUpInside];
    [newSet setTitleColor:[MobileMarcherVariables sharedVariableInstance].systemColor forState:UIControlStateNormal];
    [newSet.layer setBorderColor:[[MobileMarcherVariables sharedVariableInstance].systemColor CGColor]];
    [newSet.layer setBorderWidth:1];
    [newSet.titleLabel setFont:[UIFont systemFontOfSize:15]];
    [newSet setTitle:[NSString stringWithFormat:@"%i",totalNumberOfSets] forState:UIControlStateNormal];
    [scrollviewMusic addSubview:newSet];
    [arrayofSetButtons addObject:newSet];

    // Add gesture recognizer
    //
    UILongPressGestureRecognizer *showHandlesLongPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(showHandles:)];
    showHandlesLongPress.minimumPressDuration = .5;
    [newSet addGestureRecognizer:showHandlesLongPress];

    if (doWeAddItToTheDatabase) [[NSNotificationCenter defaultCenter] postNotification:newSetNotification];

}