屏幕快照 2016-09-29 14.44.38.png
点击按钮，使用线程下载网络图片
@property (strong, nonatomic) IBOutlet UIImageView *iv;
@property (strong, nonatomic) IBOutlet UIButton *btn;
- (IBAction)showImage:(id)sender;
- (IBAction)showImage:(id)sender {
NSString *url = @"http://ppt.downhot.com/d/file/p/2014/07/24/e8660d99f4cf021d4f0fc80b11902779.jpg";
NSThread *thread = [[NSThread alloc] initWithTarget:self selector:@selector(downloadImageFormURL:) object:url];
[thread start];
}
//定义一个方法作为线程的执行体
-(void)downloadImageFormURL:(NSString *)url{
//从网络获取数据
NSData *data = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:url]];
UIImage *image = [[UIImage alloc] initWithData:data];
if (image != nil) {
//在主线程中执行updateUI：的方法
[self performSelectorOnMainThread:@selector(updateUI:) withObject:image waitUntilDone:YES];
}
else{
NSLog(@"----下载图片出现错误----");
}
}
-(void)updateUI:(UIImage *)image{
self.iv.image = image;
}
