Will的部落格

UIScrollView可幫助我們在手機顯示的小畫面中瀏覽大圖，

將大圖複製進xcode後，在套入以下程式碼即可執行。

viewController.h

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController<UIScrollViewDelegate>
{
    UIImageView *imageView;
    UILabel *scaleRatioLabel;
}

@end

viewController.m

#import "ViewController.h"

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UIScrollView *myScrollView;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    UIImage *myImage = [UIImage imageNamed:@"2013-06-13 20.02.00.jpg"];
    imageView = [[UIImageView alloc]initWithImage:myImage];
    [imageView setFrame:CGRectMake(0, 0, 2268, 568)];
    [_myScrollView addSubview:imageView];
    
    _myScrollView.contentSize = myImage.size;
    _myScrollView.minimumZoomScale = 1.0f;
    _myScrollView.maximumZoomScale = 5.0f;
    _myScrollView.zoomScale = 1.0f;
    
    scaleRatioLabel = [[UILabel alloc]initWithFrame:CGRectMake(320 / 2 - 50 / 2, 568 / 2 - 25 / 2, 50, 25)];
    [scaleRatioLabel setBackgroundColor:[UIColor clearColor]];
    [self.view addSubview:scaleRatioLabel];
}

- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale
{
    [self.view bringSubviewToFront:scaleRatioLabel];
    [scaleRatioLabel setAlpha:0.6f];
    [scaleRatioLabel setBackgroundColor:[UIColor lightGrayColor]];
    scaleRatioLabel.text = [NSString stringWithFormat:@"x%.1f", scale];
    [UIView transitionWithView:scaleRatioLabel duration:2.0f options:UIViewAnimationOptionCurveEaseInOut animations:^(void){scaleRatioLabel.alpha = 0.0f;} completion:nil];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    return imageView;
}

@end