objective-c - 同时使用 UILongPressGestureRecognizer 和 UISwipeGestureRecognizer

Question

我使用长按手势创建了一个简单的 View (黑色方 block )并将其拖动到屏幕上 (UIGestureRecognizerStateChanged)，直到我捕捉到 UIGestureRecognizerStateEnded。好的，这很好用。现在我希望能够开始识别这个黑色方形 View 的其他手势 (UISwipeGestureRecognizer)。算法很简单:

1. 长按创建黑色方 block
2. 手指停留在屏幕上
3. 拖动正方形 View (setCenter:)
4. 滑动并识别 UISwipeGestureRecognizer

问题是在长按手势未完成时无法识别滑动(UIGestureRecognizerStateEnded)

#pragma mark - View lifecycle

- (void)loadView {
    [super loadView];

    // Long press
    self.longPressGestureRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(gestureAction:)];
    [self.longPressGestureRecognizer setDelegate:self];
    [self.view addGestureRecognizer:self.longPressGestureRecognizer];

    // Swipe
    self.swipeGestureRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(gestureAction:)];
    [self.swipeGestureRecognizer setDelegate:self];
    [self.swipeGestureRecognizer setEnabled:NO];
    [self.view addGestureRecognizer:self.swipeGestureRecognizer];
}

#pragma mark - Gesture recognizer

- (void)gestureAction:(UIGestureRecognizer *)recognizer {

    // Swipe
    if ([recognizer isKindOfClass:NSClassFromString(@"UISwipeGestureRecognizer")]) {
        NSLog(@"swipeGestureRecognizer handled!!");
    }

    // Long press
    if ([recognizer isKindOfClass:NSClassFromString(@"UILongPressGestureRecognizer")]) {
        if (recognizer.state == UIGestureRecognizerStateBegan) {
            self.activeView = [[ItemView alloc] initWithFrame:CGRectMake(0, 0, 100, 100)];
            [self.activeView setBackgroundColor:[UIColor blackColor]];
            self.activeView.center = [recognizer locationInView:self.view];
            [self.view addSubview:self.activeView];
        }
        else if (recognizer.state == UIGestureRecognizerStateChanged) {
            if (![self.swipeGestureRecognizer isEnabled]) {
                [self.swipeGestureRecognizer setEnabled:YES];
                NSLog(@"swipeGestureRecognizer enabled");
            }
            self.activeView.center = [recognizer locationInView:self.view];
        }
        else if (recognizer.state == UIGestureRecognizerStateEnded) {
            [self.swipeGestureRecognizer setEnabled:NO];
            NSLog(@"swipeGestureRecognizer disabled");
            [self.activeView removeFromSuperview];
            self.activeView = nil;
        }
    }
}

#pragma mark - UIGestureRecognizerDelegate

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
    return YES;
}

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
    return YES;
}

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
    return YES;
}

---

附言当您长按在日期 Canvas 上创建事件时，我希望其行为与 native 日历应用程序中的行为完全相同。如果您滑动某个对象(在结束长按手势之前)，它会顺利消失。

Answer 1

要同时识别多个手势，您需要使用 UiGestureRecognizer 协议(protocol)中的以下委托(delegate)方法，

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer;

这是 LINK到文档。

编辑

所以我尝试做同样的事情，是的，即使在我的情况下，直到长按结束才识别出滑动......!所以如果你想四处移动 View ，那么使用 PanGesture 而不是滑动手势..!它会工作我刚刚试过..:)