如何在滑动时更改 UIView 背景颜色

Question

如何通过滑动手势更改UIView背景颜色？ 例如，绿色表示左滑动，红色表示右滑动。 谢谢。

代码不起作用：

- (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

您需要单独的滑动处理程序才能使其工作。这很好用。

设置UISwipeGestureRecognizer的代码应该看起来 喜欢这个。

 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];

你的滑动手柄应该是这样的。

- (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];
}

Answer 2

在 ViewController 文件的interface中声明一个 imageView 属性。 @property(弱，非原子(UIImageView *imageView;

- (void)viewDidLoad
    {
    [super viewDidLoad];
  self.imageView = [[UIImageView alloc]initWithFrame:CGRectMake(100.0, 100.0, 100.0, 100.0)];
    [imageView setUserInteractionEnabled:YES];
    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.imageView addGestureRecognizer:swipeLeft];
    [self.imageView addGestureRecognizer:swipeRight];
    }

处理轻扫手势事件newImage 和 newImage1 是 project 或 ImageAssets 中的图像文件名 - (无效(句柄滑动：(UISwipeGestureRecognizer *(swipe {

    if (swipe.direction == UISwipeGestureRecognizerDirectionLeft) {
        NSLog(@"Left Swipe");
self.view.backgroundColor = [UIColor greenColor];
self.imageView.image = [UIImage imageNamed: @"myNewImage.png"];
    }
    if (swipe.direction == UISwipeGestureRecognizerDirectionRight) {
        NSLog(@"Right Swipe");   
    self.view.backgroundColor = [UIColor redColor];
    self.imageView.image = [UIImage imageNamed: @"myNewImage1.png"];
    } 
}

希望这有帮助。快乐编码。请参阅此 SO 帖子