OS开发多线程篇—线程间的通信

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@interface BTThreadViewController ()

{

    UIImageView *imagev;

}

@end

- (void)viewDidLoad

{

    [super viewDidLoad];

    imagev = [[UIImageView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];

    [self.view addSubview:imagev];

    //子线程里面调用downImage方法下载图片

    [self performSelectorInBackground:@selector(downImage) withObject:nil];

}

-(void)downImage

{

    //从网络中下载图片

    NSURL *url = [NSURL URLWithString:@"http://i8.topit.me/8/c1/31/1142319854bdc31c18o.jpg"];

    //将图片转换为二进制数据

    NSData *imgData = [NSData dataWithContentsOfURL:url];

    //数据转换成图片

    UIImage *img = [UIImage imageWithData:imgData];

    //回到主线程设置图片

    [self performSelectorOnMainThread:@selector(senderImage:) withObject:img waitUntilDone:NO];

}

-(void)senderImage:(UIImage *)image

{

    imagev.image = image;

}