Cocos2d 检测 UIGestureRecognizer 何时上下左右

Question

我有一个 CCSprite，我想使用手势来移动它。问题是我对 Cocos2D 完全陌生。我希望我的精灵在手势向上时执行一个动作，在手势向下时执行另一个动作，在手势向右时执行另一个动作，在向左时执行相同的操作。有人能指出我正确的方向吗？

谢谢！

Answer 1

显然每个 UISwipeGestureRecognizer 只能检测给定方向的滑动。即使方向标志可以进行“或”运算，UISwipeGestureRecognizer 也会忽略其他标志。

解决方案是为您想要识别滑动手势的每个方向添加一个 UISwipeGestureRecognizer，并将每个识别器的方向相应地设置为上、下、左、右。如果您想测试任意方向的滑动，则必须添加四个 UISwipeGestureRecognizer。

这有点奇怪，但这是对我有用的唯一方法。

Answer 2

UISwipeGestureRecognizer *swipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeGesture:)];
swipeGesture.direction = UISwipeGestureRecognizerDirectionUp|UISwipeGestureRecognizerDirectionDown;
[self.gestureAreaView addGestureRecognizer:swipeGesture];
[swipeGesture release];

-(void)handleSwipeGesture:(UISwipeGestureRecognizer *) sender 
{
    //Gesture detect - swipe up/down , can't be recognized direction
}

or

UISwipeGestureRecognizer *swipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeGesture:)];
swipeGesture.direction = UISwipeGestureRecognizerDirectionUp;
[self.view addGestureRecognizer:swipeGesture];
[swipeGesture release];

UISwipeGestureRecognizer *swipeGesture2 = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeGesture:)];
swipeGesture2.direction = UISwipeGestureRecognizerDirectionDown;
[self.view addGestureRecognizer:swipeGesture2];
[swipeGesture2 release];

-(void)handleSwipeGesture:(UISwipeGestureRecognizer *) sender 
{
    //Gesture detect - swipe up/down , can be recognized direction
    if(sender.direction == UISwipeGestureRecognizerDirectionUp)
    {
    }
    else if(sender.direction == UISwipeGestureRecognizerDirectionDown)
    {
    }
}

Answer 3

使用 UIPanGestureRecogizer 并检测您关心的滑动方向。有关详细信息，请参阅 UIPanGestureRecognizer 文档。 -rh

// add pan recognizer to the view when initialized
UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panRecognized:)];
[panRecognizer setDelegate:self];
[self addGestureRecognizer:panRecognizer]; // add to the view you want to detect swipe on


-(void)panRecognized:(UIPanGestureRecognizer *)sender
{
    if (sender.state == UIGestureRecognizerStateBegan) {
        // you might want to do something at the start of the pan
    }

    CGPoint distance = [sender translationInView:self]; // get distance of pan/swipe in the view in which the gesture recognizer was added
    CGPoint velocity = [sender velocityInView:self]; // get velocity of pan/swipe in the view in which the gesture recognizer was added
    float usersSwipeSpeed = abs(velocity.x); // use this if you need to move an object at a speed that matches the users swipe speed
    NSLog(@"swipe speed:%f", usersSwipeSpeed);
    if (sender.state == UIGestureRecognizerStateEnded) {
        [sender cancelsTouchesInView]; // you may or may not need this - check documentation if unsure
        if (distance.x > 0) { // right
            NSLog(@"user swiped right");
        } else if (distance.x < 0) { //left
            NSLog(@"user swiped left");
        }
        if (distance.y > 0) { // down
            NSLog(@"user swiped down");
        } else if (distance.y < 0) { //up
            NSLog(@"user swiped up");
        }
        // Note: if you don't want both axis directions to be triggered (i.e. up and right) you can add a tolerence instead of checking the distance against 0 you could check for greater and less than 50 or 100, etc.
    }
}

Answer 4

默认方向是 UISwipeGestureRecognizerDirectionRight。也可以这样指定多个方向：

[swipeGesture setDirection: UISwipeGestureRecognizerDirectionRight|UISwipeGestureRecognizerDirectionLeft];

///
但是如果你想获得每个方向，就像这样：

 UISwipeGestureRecognizer *swipeGestureR = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeGestureRight:)];
[swipeGestureR setDirection: UISwipeGestureRecognizerDirectionRight ];
 [[[CCDirector sharedDirector] openGLView] addGestureRecognizer:swipeGestureR];

[swipeGestureR release];

UISwipeGestureRecognizer *swipeGestureL = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeGestureLeft:)];
[swipeGestureL setDirection: UISwipeGestureRecognizerDirectionLeft];
[[[CCDirector sharedDirector] openGLView] addGestureRecognizer:swipeGestureL];

[swipeGestureL release];

向左滑动时将调用函数handleSwipeGestureLeft，向右滑动时将调用handleSwipeGestureRight

Answer 5

为每个斧头（水平和垂直）添加一个 UISwipeGestureRecognizer：

UISwipeGestureRecognizer *horizontalSwipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(action)];
[horizontalSwipe setDirection:(UISwipeGestureRecognizerDirectionRight |
                           UISwipeGestureRecognizerDirectionLeft )];

[self.view addGestureRecognizer:horizontalSwipe];

UISwipeGestureRecognizer *verticalSwipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(action)];
[verticalSwipe setDirection:(UISwipeGestureRecognizerDirectionUp |
                     UISwipeGestureRecognizerDirectionDown )];

[self.view addGestureRecognizer:verticalSwipe];

Answer 6

尽管这里有很多好的信息，但我找不到包含所有信息的快速答案。

如果您想区分滑动是向左还是向右、向上还是向下，您需要为每个方向创建一个新 UISwipeGestureRecognizer。

但是！这还不错，因为您可以将每个手势识别器路由到同一个选择器，然后可以按照您的预期使用 switch 语句。

首先，为每个方向添加手势识别器，并将它们路由到同一个选择器：

- (void)setupSwipeGestureRecognizers
{
    UISwipeGestureRecognizer *rightSwipeGestureRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(userDidSwipeScreen:)];
    rightSwipeGestureRecognizer.direction = UISwipeGestureRecognizerDirectionRight;
    UISwipeGestureRecognizer *leftSwipeGestureRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(userDidSwipeScreen:)];
    leftSwipeGestureRecognizer.direction = UISwipeGestureRecognizerDirectionLeft;
    [self.view addGestureRecognizer:rightSwipeGestureRecognizer];
    [self.view addGestureRecognizer:leftSwipeGestureRecognizer];
}

第二，使用 switch 语句区分方向：

- (void)userDidSwipeScreen:(UISwipeGestureRecognizer *)swipeGestureRecognizer
{
    switch (swipeGestureRecognizer.direction) {
        case UISwipeGestureRecognizerDirectionLeft: {
            // Handle left
            break;
        }
        case UISwipeGestureRecognizerDirectionRight: {
            // Handle right
            break;
        }
        default: {
            break;
        }
    }
}

Answer 7

-(void)addGesture {
UISwipeGestureRecognizer *swipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeGesture:)];
    [self.view addGestureRecognizer:swipeGesture];
    [swipeGesture release];
}

-(void)handleSwipeGesture:(UISwipeGestureRecognizer *) sender {

if (sender.direction == UISwipeGestureRecognizerDirectionUp) {
  //do something
 }
else if (sender.direction == UISwipeGestureRecognizerDirectionDown) {
  //do something
 }
else if (sender.direction == UISwipeGestureRecognizerDirectionLeft) {
  //do something
 }
else if (sender.direction == UISwipeGestureRecognizerDirectionRight) {
  //do something
 }


}

还可以使用 switch 代替所有 if 语句