ViewController.h

1 #import 
     
       2  3 @interface ViewController : UIViewController 4 
      
        5 { 6     UIImageView* imageView; 7     NSMutableData* imageData; 8 } 9 10 @end
      
     

ViewController.m

1 #import "ViewController.h" 2  3 @implementation ViewController 4  5 #pragma mark - viewDidLoad Event 6 -(void)initImageViewFData 7 { 8     imageData = [[NSMutableData alloc] init]; 9     imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 320, 240)];10     [self.view addSubview:imageView];11     [imageView release];12 }13 -(void)startDownloadFImage14 {15     NSString* str = @"http://192.168.88.8/sns/my/headimage.php?uid=865";16     NSURL* url = [NSURL URLWithString:str];17     18     //建立一个请求，设置url，缓存，超时时间19     NSURLRequest* request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:60.0];20     //发送同步请求21     //NSData* data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];22     //异步请求23     [NSURLConnection connectionWithRequest:request delegate:self];24     //开始下载图片,什么时候知道下载完数据了25 }26 27 #pragma mark - viewDidLoad28 - (void)viewDidLoad29 {30     [super viewDidLoad];31     //初始.h里的字段32     [self initImageViewFData];33     //开始下载图片34     [self startDownloadFImage];35 }36 37 38 #pragma mark - NSURLConnectionDataDelegate39 //下载完响应头，准备下载内容40 - (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{41     [imageData setLength:0];42     [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;43 }44 //下载数据 , 多次调用45 - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{46     //追加数据47     [imageData appendData:data];48 }49 //调用这个方法，证明下载完成50 - (void)connectionDidFinishLoading:(NSURLConnection *)connection{51     UIImage* image = [UIImage imageWithData:imageData];52     imageView.image = image;53      [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;54 }55 //下载失败56 - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{57     NSLog(@"下载失败");58 }