Ios 使用UIScrollView滚动UIImage

我正试图让我的图像可以

平移

和

缩放

，但我似乎无法让它工作

这是我的注释代码>创建

UIScrollView

>创建

PFImageView

（

UIImage

）>将图像添加到

UIScrollView

>获取和显示图像

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    NSLog(@"%@",_courseObject);                         //checking object has loaded

    UIScrollView *scrollView = [[UIScrollView alloc] init];
    scrollView.frame = self.view.bounds;                //scroll view occupies full parent view!
    scrollView.contentSize = CGSizeMake(400, 800);      //scroll view size
    scrollView.showsVerticalScrollIndicator = YES;      //to hide scroll indicators!
    scrollView.showsHorizontalScrollIndicator = YES;    //by default, it shows!
    scrollView.scrollEnabled = YES;                     //say "NO" to disable scroll
    [self.view addSubview:scrollView];                  //adding to parent view!



    PFImageView *mapImage = [[PFImageView alloc] init];         //create imageview
    mapImage.frame = self.navigationController.view.frame;      //set image boundaries to fill nav frame(!)
    mapImage.image = [UIImage imageNamed:@"loading"];           //placeholder image
    mapImage.file = (PFFile *)[_courseObject objectForKey:@"file"]; //retrieve the map image

    [scrollView addSubview:mapImage];                               //add the mapImage to scrollView
    [mapImage loadInBackground];                                    //retrieve image and add

}

---

您需要使用滚动视图委托，更具体地说，您需要实现以下方法：

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView

（PFImageView*mapImage必须成为属性而不是局部变量）

---

这里的问题是scrollView.contentSize不够大，因此当尝试滚动时，它没有拾取移动

通过更改值以填充帧以及实现委托协议，我可以使用滚动视图

UIScrollView *scrollView = [[UIScrollView alloc]initWithFrame:self.view.bounds];

UIScrollView *scrollView = [[UIScrollView alloc]initWithFrame:self.view.bounds];