如何在滑动时更改 UIView 背景颜色？答案

【问题标题】：How to change a UIView background colour upon swipe?如何在滑动时更改 UIView 背景颜色？
【发布时间】：2017-08-19 18:41:47
【问题描述】：

如何通过 SwipeGesture 更改 UIView 背景颜色？例如绿色表示左滑，红色表示右滑。非常感谢。

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");
        }

    }

【问题讨论】：

您应该展示一些您尝试过但没有工作的代码，如果您没有尝试任何东西，我建议您在询问之前先做：)
请在下面查看我的答案。
@TallentSiu 我为你添加了一个工作代码。请在下面查看。如果您发现它有效，我很感激投票和/或接受答案。 :) 乐于助人。

标签： ios objective-c xcode uiview uibackgroundcolor

【解决方案1】：

您需要有单独的滑动处理程序才能使其工作。这很好用。

您在设置 UISwipeGestureRecognizer 时的代码应如下所示像这样。

 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];
}

【讨论】：

【解决方案2】：

在 ViewController 文件的interface 中声明一个 imageView 属性。 @property (weak, nonatomic) 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];

    }

处理滑动手势事件 //newImage 和 newImage1 是 project 或 ImageAssets 中的图像文件名 - (void)handleSwipe:(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"];
    } 

}

希望这会有所帮助。快乐编码。 refer to this SO Post

【讨论】：

感谢您的回复，但您的代码不适用于我的情况，因为它会首先更改 imageView，然后仅更改第二次滑动的背景颜色。我可以通过一次滑动同时更改 imageView 和背景颜色吗？谢谢。
是的，你想什么时候改变 imageView
您需要将imageView声明为属性并更改图像。请检查我的更新答案。