iPhone应用开发之四：UIImageView和UIWebView的详细讲解
From:?http://www.2cto.com/kf/201111/111885.html
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Andy-清风原创，转载请注明，谢谢。
1.UIImageView的讲解
（1）初始化
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UIImageView? *imageView =[[UIImageView alloc] initWithFrame:CGRectMake(0.0,45.0,300,300)];?
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imageView.image = [UIImage imageNamed:@"a.png"];//加载入图片?
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[self.view addSubView:image];?
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也可以这样声明：
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UIImage *image =[[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:[NSURLURLWithString:@"http://farm4.static.flickr.com/3092/2915896504_a88b69c9de.jpg"]]];?
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];??
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在加载入图片的时候有两种加载UIImage的方法：如下：
-》1
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[UIImage imageNamed:@"a.png"];?
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-》2
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NSString *path = [[NSBundle mainBundle] pathForResource:@”icon”?
ofType:@”png”];?
myImage = [UIImage imageWithContentsOfFile:path];?
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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.
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NSImage *image = [[NSImage alloc]initWithContentsOfURL:(NSURL *)];?
NSImage *image = [[NSImage alloc]initWithContentsOfFile:(NSString *)];?
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最后要记得释放掉image。
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（2）利用UIImageView实现幻灯片效果
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利用UIImageView和UISider来制作幻灯片。
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ImagesViewController.h?
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#import<UIKit/UIKit.h>?
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@interfaceImagesViewController : UIViewController?
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{?
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???????? UIImageView *imageView;?
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???????? UISlider *slider;?
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}?
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@property (nonatomic,retain) IBOutlet UIImageView *imageView;?
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@property (nonatomic,retain) IBOutlet UISlider *slider;?
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-(IBAction)sliderAction:(id)sender;?
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@end?
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ImagesViewController.m?
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#import"ImagesViewController.h"?
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#import"Constants.h"?
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#define kMinDuration 0.0?
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#define kMaxDuration 10.0?
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@implementationImagesViewController?
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@synthesize imageView,slider;?
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- (void)dealloc?
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{?
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???????? [imageView release];?
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???????? [slider release];?
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???????? [super dealloc];?
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- (void)viewDidLoad?
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{????????
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???????? [super viewDidLoad];?
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???????? self.title = NSLocalizedString(@"ImagesTitle",@"");?
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???????? self.imageView.animationImages = [NSArray arrayWithObjects:?
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????????? [UIImageimageNamed:@"scene1.jpg"],?
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????????? [UIImageimageNamed:@"scene2.jpg"],?
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????????? [UIImageimageNamed:@"scene3.jpg"],?
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????????? [UIImageimageNamed:@"scene4.jpg"],?
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????????? [UIImageimageNamed:@"scene5.jpg"],nil];?
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???????? imageView.animationDuration = 5.0;?
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???????? [self.imageView stopAnimating];?
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???????? imageView.image= [UIImage imageNamed:@"a.png"];?
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???????? [self.imageView setIsAccessibilityElement:YES];?
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???????? [self.imageView setAccessibilityLabel:self.title];?
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???????? [self.slidersetAccessibilityLabel:NSLocalizedString(@"DurationSlider",@"")];?
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}?
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- (void)viewDidUnload?
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{?
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???????? [super viewDidUnload];?
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???????? self.imageView = nil;?
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???????? self.slider = nil;?
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-(IBAction)sliderAction:(id)sender?
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{?
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???????? UISlider* durationSlider = sender;?
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???????? self.imageView.animationDuration = [durationSlider value];?
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???????? if (!self.imageView.isAnimating)?
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???????????????? [self.imageView startAnimating];?
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}?
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#pragma mark -?
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#pragma markUIViewController delegate methods?
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-(void)viewWillDisappear:(BOOL)animated?
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{????????
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???????? [self.imageView stopAnimating];?
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???????? self.navigationController.navigationBar.barStyle =UIBarStyleDefault;?
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???????? [UIApplication sharedApplication].statusBarStyle =UIStatusBarStyleDefault;?
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}?
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-(void)viewWillAppear:(BOOL)animated?
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{????????
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???????? [self.imageView startAnimating];?
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???????? self.navigationController.navigationBar.barStyle =UIBarStyleBlackOpaque;?
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???????? [UIApplication sharedApplication].statusBarStyle =UIStatusBarStyleBlackOpaque;?
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}?
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@end?
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首先通过加载多张图片进入imageView的animationImages里面。再设置动画的时间间隔animationDuration，并设置UISider控制幻灯片播放的速度，让图片像幻灯片那么播放。
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2.UIWebView的讲解
(1)初始化
在.h文件中声明UIWebView。
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@interface WebViewController :UIViewController {?
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IBOutlet UIWebView *webView;?
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@property (nonatomic,retain) UIWebView *webView;?
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@end?
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在.m文件中初始化UIWebView并载入要读取的URL，如下：
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- (void)viewDidLoad {?
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NSString *urlAddress =@”http://www.google.com”;?
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//Create a URL object.?
NSURL *url = [NSURL URLWithString:urlAddress];?
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//URL Requst Object?
NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];?
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//Load the request in theUIWebView.?
[webView loadRequest:requestObj];?
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并在你的delegate里面载入跟IB一起的XIB文件，如下：
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-(void)applicationDidFinishLaunching:(UIApplication *)application {?
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self.wvTutorial =[[WebViewController alloc] initWithNibName:@”WebView” bundle:[NSBundlemainBundle]];?
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[windowaddSubview:[wvTutorial view]];?
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// Override point forcustomization after app launch?
[window makeKeyAndVisible];?
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今天就讲UIImageView和UIWebView的利用，这两个都是比较有用的，在以后的开发中布局会经常用到，最后，谢谢大家支持。欢迎大家拍砖。
