ios - 如何在滑动时更改 UIView 背景颜色？

Question

如何通过 SwipeGesture 更改 UIView 背景颜色？例如向左滑动为绿色，向右滑动为红色。非常感谢。

代码不工作:

- (void)viewDidLoad {

    self.view.backgroundColor=[[UIColor alloc]initWithRed:24.0/255 green:96.0/255 blue:120.0/255 alpha:0.5];

    UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(100.0, 100.0, 100.0, 100.0)];
    [imageView setUserInteractionEnabled:YES];

    [super viewDidLoad];

    UISwipeGestureRecognizer *swipeLeft = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipe:)];
    UISwipeGestureRecognizer *swipeRight = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipe:)];

    // Setting the swipe direction.
    [swipeLeft setDirection:UISwipeGestureRecognizerDirectionLeft];
    [swipeRight setDirection:UISwipeGestureRecognizerDirectionRight];

    // Adding the swipe gesture on image view
    [self.view addGestureRecognizer:swipeLeft];
    [self.view addGestureRecognizer:swipeRight];
}

    - (void)handleSwipe:(UISwipeGestureRecognizer *)swipe {

        if (swipe.direction == UISwipeGestureRecognizerDirectionLeft) {

            self.view.backgroundColor=[[UIColor alloc]initWithRed:138.0/255 green:24.0/255 blue:47.0/255 alpha:1.0];
            NSLog(@"Left Swipe");
        }

        if (swipe.direction == UISwipeGestureRecognizerDirectionRight) {

            self.view.backgroundColor=[[UIColor alloc]initWithRed:24.0/255 green:96.0/255 blue:120.0/255 alpha:1.0];
            NSLog(@"Right Swipe");
        }

    }

Answer 1

您需要有单独的滑动处理程序才能使其正常工作。这很好用。

Your codes in setting up your UISwipeGestureRecognizer should look like this.

 UISwipeGestureRecognizer *swipeRight = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeRight:)];
    UISwipeGestureRecognizer *swipeLeft = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeLeft:)];

    swipeRight.direction = UISwipeGestureRecognizerDirectionRight;
    swipeLeft.direction = UISwipeGestureRecognizerDirectionLeft;
    imageView.userInteractionEnabled = YES;
    // Adding the swipe gesture on image view
    [imageView addGestureRecognizer:swipeRight];
    [imageView addGestureRecognizer:swipeLeft];

And your swipe handle should be like this.

- (void)handleSwipeRight:(UISwipeGestureRecognizer *)swipe {
    self.view.backgroundColor=[[UIColor alloc]initWithRed:24.0/255 green:96.0/255 blue:120.0/255 alpha:1.0];
}

- (void)handleSwipeLeft:(UISwipeGestureRecognizer *)swipe {
    self.view.backgroundColor=[[UIColor alloc]initWithRed:138.0/255 green:24.0/255 blue:47.0/255 alpha:1.0];
}