iOS - Training (11) - UIScrollView

用於瀏覽內容畫面比Device畫面還大時，可以藉由托拉、放大、縮小的方式調整畫面。

參數：

• contentSize: 決定UIScrollView可以scroll的範圍，通常UIScrollView的size會比contentSize來的小。
• contentOffset: UIScrollView左上角的點與content邊界的遍移值。在托拉UIScrollView時，此值會一直變化。

ViewController.h

加入UIScrollView與UIImageView元件

@interface ViewController : UIViewController {     IBOutlet UIScrollView *myScroll;     UIImageView* contentImgView; } @end

ViewController.m

- (void)viewDidLoad {     [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib.     int imgWidth = 352;     int imgHeight = 500;          contentImgView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"minami.jpg"]];     contentImgView.frame = CGRectMake(0.0, 0.0, imgWidth, imgHeight);          myScroll.contentSize = CGSizeMake(imgWidth, imgHeight);     [myScroll addSubview:contentImgView];          // 加入放大縮小功能     myScroll.delegate = self; // 會去調用viewForZoomingInScrollView方法     myScroll.maximumZoomScale = 1;     myScroll.minimumZoomScale = myScroll.bounds.size.height / contentImgView.bounds.size.height;          // 畫面起始大小與內容大小一樣     [myScroll zoomToRect:CGRectMake(0.0, 0.0, imgWidth, imgHeight) animated:YES]; } // 加入此方法才會被調用放大縮小功能 - (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {     return contentImgView; }

分頁效果 (類似Android的Gallery)-----

- (void)viewDidLoad {     [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib.     int imgNum = 3;     float imgWidth = 240;     float imgheight = 240;          myScroll.contentSize = CGSizeMake(imgNum*imgWidth, imgheight);          for(int i = 0;i < imgNum;i++)     {         UIImageView* imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:[NSString stringWithFormat:@"page%d.jpg", i+1]]];         imageView.frame = CGRectMake(i*imgWidth, 0, imgWidth, imgheight);                  [myScroll addSubview:imageView];     }     myScroll.pagingEnabled = YES; // 分頁效果     myScroll.delegate = self; // 調用UIScrollViewDelegate裡的scrollViewDidScroll方法 } - (void)scrollViewDidScroll:(UIScrollView *)scrollView {     CGRect bounds = scrollView.bounds;     NSLog(@"Bounds %f, %f, %f, %f", bounds.origin.x, bounds.origin.y, bounds.size.width, bounds.size.height); }

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資料出處《Object-C與iOS開發入門》