ipad实现ScrollView通过手势滚动和缩放的Image



	 

	在ipad上预览一张图片的时候，如果我们希望能够够缩放和滚动(类似与google地图效果)，需要使用ScrollView

	 

	-------视图控制器定义如下

	 

	@inte易做图ce TestBedViewController : UIViewController <UIScrollViewDelegate>

	 

	{

	 

	UIImage *weathermap;

	 

	}

	 

	@property (retain) UIImage *weathermap;

	 

	@end

	 

	 

	@implementation TestBedViewController

	 

	@synthesize weathermap;

	 

	//在通过缩放手势的时候制定，所有ScrollView中的Image

	 

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

	 

	{

	 

	return [self.view viewWithTag:201];

	 

	}

	 

	 

	/*

	 

	- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(float)scale

	 

	{

	 

	}

	 

	*/

	 

	 

	- (void) viewDidLoad

	 

	{

	 

	 

	// 创建滚动视图并设置大小和代理对象                                                        px    py   宽度 高度

	 

	UIScrollView *sv = [[[UIScrollView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 320.0f, 284.0f)] autorelease];

	 

	sv.contentSize = self.weathermap.size;//要缩放的UIImage对象

	 

	sv.delegate = self; //设定代理对象

	 

	 

	// 创建图片对象

	 

	UIImageView *iv = [[[UIImageView alloc] initWithImage:self.weathermap] autorelease];

	 

	iv.userInteractionEnabled = YES;

	 

	iv.tag = 201;

	 

	 

	// 计算缩放数值

	 

	float minzoomx = sv.frame.size.width / self.weathermap.size.width;

	 

	float minzoomy = sv.frame.size.height / self.weathermap.size.height;

	 

	sv.minimumZoomScale = MIN(minzoomx, minzoomy);  //最小缩放到当前ScrollView的大小比例

	 

	sv.maximumZoomScale = 3.0f; //最大缩放到图片的3倍

	 

	 

	// 在scorllView添加image

	 

	[sv addSubview:iv];

	 

	[self.view addSubview:sv];

	 

	}

	 

	@end

	 

	作者sdhjob

补充：移动开发 , 其他 ,