Question

我的视图中有一个滚动条，在这个滚动条中有几个图像。

我想将这些图像拖放到我的滚动条中。我实现了LongPressGestureRecognizer。

我也想知道（通过代码）哪个图像被长按了。我以为我使用CGRectContainsPoint修复了最后一个。但是我的代码没有对CGRectContainsPoint做出反应。它仍然记录“失败”。

- (void)viewDidLoad{

    //scroller properties
    scroller.contentSize = CGSizeMake(1300, 130);
    scroller.scrollEnabled = YES;
    scroller.directionalLockEnabled =YES;
    scroller.frame = CGRectMake(0, 874, 768, 130);

    UILongPressGestureRecognizer *longPress =
    [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressed:)];

    [image1 addGestureRecognizer:longPress];
    [image2 addGestureRecognizer:longPress];
    [image3 addGestureRecognizer:longPress];
    [longPress release];

}

-(void)longPressed:(UILongPressGestureRecognizer *)sender {


    CGPoint location = [sender locationInView:self.view];

    if(CGRectContainsPoint(image1.frame,  location)) {
        NSLog(@"image1 has been longpressed");
        // do something
    }

    if(CGRectContainsPoint(image2.frame,  location)) {
        NSLog(@"image2 has been longpressed");
        // do something
    }

    if(CGRectContainsPoint(image3.frame,  location)) {
        NSLog(@"image3 has been longpressed");
        // do something


    }

         else {
                 NSLog(@"fail");
}

有人有使用此LongPressGestureRecognizer的经验以及可以响应此功能的图像数量吗？

我确实成功实现了两个手势识别器。所以我的滚动条中的图像现在可以拖动了。但是它限制在scrollview内部。我希望有一些功能可以将图像放在滚动视图的前面，这样我就可以将我的图像从滚动视图中拖出来。

在我实现的viewDidLoad方法中

[scroller addSubview:image1];
[scroller addSubview:image2];
[scroller addSubview:image3];

[[self view] addSubview:scroller];

在我的longPressed方法中我实现了

[image1 bringSubviewToFront:self.view];

有人有好的提示吗？非常感谢他们！

Answer 1

添加滚动视图并创建一个IBOutlet

在此答案中为项目添加三个图像我使用名称 image1.png，image2.png和image3.png

最后这是代码

- (void) viewDidLoad{
        [super viewDidLoad];

        for (int i=1; i<=3; i++) {
            NSString *file = [NSString stringWithFormat:@"image%d.png", i];
            UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:file]];
            imageView.frame = CGRectMake(i * 200, 0, 200, 200);
            imageView.userInteractionEnabled = YES;
            imageView.tag = i;
                      
            UILongPressGestureRecognizer *recognizer = [[UILongPressGestureRecognizer              alloc] initWithTarget:self action:@selector(longPress:)];
           
            [thumbView addGestureRecognizer:recognizer];
            [scrollView addSubview:thumbView];
        }
    }    

-(void)longPress: (UILongPressGestureRecognizer *)recognizer
{
        UIView *view  = recognizer.view;
        int index = view.tag;
        NSLog(@"image pressed : %i", índex);
}

使用这种方法，你将能够创建3个imageViews并添加一个手势识别器，代码更少，并告诉你imageView是longPressed

但是如果你想拖动imageView UILongPressGestureRecognizer对你不起作用，对于那个任务，你应该使用UIPanGestureRecognizer

如果要将imageView拖出scrollView，可以模仿该效果从scrollView中删除/隐藏imageView并添加具有相同图像的imageView 您要隐藏/移除到要拖动imageView

的视图中的imageView的确切位置

更多是视觉效果，但有效

Answer 2

只需修改您的课程如下：

 @implementation longGestureViewController

// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView 
{
    UIView *view = [[UIView alloc] initWithFrame:[UIScreen mainScreen].applicationFrame];

    self.view = view;
    self.view.tag = 100;
    [view release];

    mImageView1 = [[UIImageView alloc] initWithFrame:CGRectMake(10.0, 10.0, 100.0, 120.0)];
    mImageView1.image = [UIImage imageNamed:@"tile07.png"];
    [self.view addSubview:mImageView1];
    mImageView1.userInteractionEnabled = YES;
    mImageView1.tag = 1;
    [mImageView1 release];

    mImageView2 = [[UIImageView alloc] initWithFrame:CGRectMake(120.0, 10.0, 100.0, 120.0)];
    mImageView2.image = [UIImage imageNamed:@"tile08.png"];
    mImageView2.userInteractionEnabled = YES;
    mImageView2.tag = 2;
    [self.view addSubview:mImageView2];
    [mImageView2 release];

    mImageView3 = [[UIImageView alloc] initWithFrame:CGRectMake(10.0, 140.0, 100.0, 120.0)];
    mImageView3.image = [UIImage imageNamed:@"tile09.png"];
    mImageView3.tag = 3;
    mImageView3.userInteractionEnabled = YES;
    [self.view addSubview:mImageView3];
    [mImageView3 release];
}


// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad 
{
    [super viewDidLoad];

    UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressed:)];

    [mImageView1 addGestureRecognizer:longPress];
    [longPress release];

    longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressed:)];

    [mImageView2 addGestureRecognizer:longPress];
    [longPress release];

    longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressed:)];

    [mImageView3 addGestureRecognizer:longPress];
    [longPress release];
}

-(void)longPressed:(UILongPressGestureRecognizer *)sender 
{
    CGPoint location = [sender locationInView:self.view];
    UIView *view = [self.view hitTest:location withEvent:UIEventTypeTouches];
    NSLog(@"%d", view.tag);
}


- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}


- (void)dealloc 
{
    [super dealloc];
}

UIScrollview中的手势识别器

2 个答案: