iPhone应用开发之四：UIImageView和UIWebView的详细讲解


		
	 

	Andy-清风原创，转载请注明，谢谢。

	1.UIImageView的讲解

	（1）初始化

	 

	UIImageView  *imageView =[[UIImageView alloc] initWithFrame:CGRectMake(0.0,45.0,300,300)]; 

	 

	imageView.image = [UIImage imageNamed:@"a.png"];//加载入图片 

	 

	[self.view addSubView:image]; 

	 

	 

	也可以这样声明：

	 

	UIImage *image =[[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:[NSURLURLWithString:@"http://farm4.static.flickr.com/3092/2915896504_a88b69c9de.jpg"]]]; 

	UIImageView *imageView = [[UIImageView alloc] initWithImage:image];  

	 

	在加载入图片的时候有两种加载UIImage的方法：如下：

	-》1

	 

	[UIImage imageNamed:@"a.png"]; 

	 

	-》2

	 

	NSString *path = [[NSBundle mainBundle] pathForResource:@”icon” 

	ofType:@”png”]; 

	myImage = [UIImage imageWithContentsOfFile:path]; 

	 

	如果找到图片，装载到iPhone系统缓存图象。那意味图片是(理论上)放在内存里作为cache的。因此如果图片资源多了或大了，此方式容易引起发生内存警告从而导致自动退出的问题。

	最好是通过直接读取文件路径[UIImage imageWithContentsOfFile]解决掉这个问题.

	 

	NSImage *image = [[NSImage alloc]initWithContentsOfURL:(NSURL *)]; 

	NSImage *image = [[NSImage alloc]initWithContentsOfFile:(NSString *)]; 

	 

	 

	最后要记得释放掉image。

	 

	 

	（2）利用UIImageView实现幻灯片效果

	 

	利用UIImageView和UISider来制作幻灯片。

	 

	ImagesViewController.h 

	 

	#import<UIKit/UIKit.h> 

	 

	  

	 

	@interfaceImagesViewController : UIViewController 

	 

	{ 

	 

	         UIImageView *imageView; 

	 

	         UISlider *slider; 

	 

	} 

	 

	  

	 

	@property (nonatomic,retain) IBOutlet UIImageView *imageView; 

	 

	@property (nonatomic,retain) IBOutlet UISlider *slider; 

	 

	  

	 

	-(IBAction)sliderAction:(id)sender; 

	 

	  

	 

	@end 

	 

	  

	 

	ImagesViewController.m 

	 

	 

	 

	#import"ImagesViewController.h" 

	 

	#import"Constants.h" 

	 

	 

	 

	#define kMinDuration 0.0 

	 

	#define kMaxDuration 10.0 

	 

	  

	 

	@implementationImagesViewController 

	 

	  

	 

	@synthesize imageView,slider; 

	 

	  

	 

	- (void)dealloc 

	 

	{ 

	 

	         [imageView release]; 

	 

	         [slider release]; 

	 

	         

	 

	         [super dealloc]; 

	 

	} 

	 

	  

	 

	- (void)viewDidLoad 

	 

	{        

	 

	         [super viewDidLoad]; 

	 

	         

	 

	         self.title = NSLocalizedString(@"ImagesTitle",@""); 

	 

	         self.imageView.animationImages = [NSArray arrayWithObjects: 

	 

	          [UIImageimageNamed:@"scene1.jpg"], 

	 

	          [UIImageimageNamed:@"scene2.jpg"], 

	 

	          [UIImageimageNamed:@"scene3.jpg"], 

	 

	          [UIImageimageNamed:@"scene4.jpg"], 

	 

	          [UIImageimageNamed:@"scene5.jpg"],nil]; 

	 

	         imageView.animationDuration = 5.0; 

	 

	         [self.imageView stopAnimating]; 

	 

	         imageView.image= [UIImage imageNamed:@"a.png"]; 

	 

	         [self.imageView setIsAccessibilityElement:YES]; 

	 

	         [self.imageView setAccessibilityLabel:self.title]; 

	 

	         [self.slidersetAccessibilityLabel:NSLocalizedString(@"DurationSlider",@"")]; 

	  

	} 

	 

	- (void)viewDidUnload 

	 

	{ 

	 

	         [super viewDidUnload]; 

	 

	         

	 

	         self.imageView = nil; 

	 

	         self.slider = nil; 

	 

	} 

	 

	-(IBAction)sliderAction:(id)sender 

	 

	{ 

	 

	         UISlider* durationSlider = sender; 

	 

	         self.imageView.animationDuration = [durationSlider value]; 

	 

	         if (!self.imageView.isAnimating) 

	 

	                 [self.imageView startAnimating]; 

	 

	} 

	 

	 

	 

	 

	 

	#pragma mark - 

	 

	#pragma markUIViewController delegate methods 

	 

	  

	 

	  

	 

	-(void)viewWillDisappear:(BOOL)animated 

	 

	{        

	 

	         [self.imageView stopAnimating]; 

	 

	  

	 

	         self.navigationController.navigationBar.barStyle =UIBarStyleDefault; 

	 

	         [UIApplication sharedApplication].statusBarStyle =UIStatusBarStyleDe

补充：移动开发 , IOS ,