NSThread

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- (void)viewDidLoad {

    [super viewDidLoad];

//    [self layout];

    UIButton *but=[[UIButton alloc]initWithFrame:CGRectMake(50, 500, 275, 30)];

    [but setTitle:@"下一页" forState:UIControlStateNormal];

    [but addTarget:self action:@selector(jump) forControlEvents:UIControlEventTouchUpInside];

    [but setTitleColor:[UIColor redColor] forState:UIControlStateNormal];

    [but setTitleColor:[UIColor redColor] forState:UIControlStateHighlighted];

    [self.view addSubview:but];

 

}

-(void)jump{

    ThreadViewController *con=[[ThreadViewController alloc]init];

    [self presentViewController:con animated:NO completion:nil];

}

-(void)layout{

    _image=[[UIImageView alloc]initWithFrame:[UIScreen mainScreen].bounds];

    _image.contentMode=UIViewContentModeScaleAspectFit;//图片居中

    [self.view addSubview:_image];

    UIButton *but=[[UIButton alloc]initWithFrame:CGRectMake(50, 500, 275, 30)];

    [but setTitle:@"下载" forState:UIControlStateNormal];

    [but addTarget:self action:@selector(loadImage) forControlEvents:UIControlEventTouchUpInside];

    [but setTitleColor:[UIColor redColor] forState:UIControlStateNormal];

    [but setTitleColor:[UIColor redColor] forState:UIControlStateHighlighted];

    [self.view addSubview:but];

}

//非多线程

//-(void)loadImage{

//    NSData *data=[NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://scimg.jb51.net/allimg/160815/103-160Q509544OC.jpg"]];

//    UIImage *imaged=[UIImage imageWithData:data];

//    _image.image=imaged;

//}

#pragma mark

//多线程(使用线程添加图片)

-(void)loadImage{

//    NSThread *thread=[[NSThread alloc]initWithTarget:self selector:@selector(myThread) object:nil];

//    [thread start];//执行线程  (启动线程，并不代表立即执行。而是出于一种就绪状态，当系统调用时才真正执行)

    //方法2 ：使用类方法

    

    [NSThread detachNewThreadSelector:@selector(myThread) toTarget:self withObject:nil];

}

#pragma mark 子线程中的操作

-(void)myThread{

    NSLog(@"===进线程了===");

    NSData *data=[NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://scimg.jb51.net/allimg/160815/103-160Q509544OC.jpg"]];

//    UIImage *imaged=[UIImage imageWithData:data];

//        _image.image=imaged;

    //这个方法是NSObject的分类方法，每个NSObject对象都有这个方法

    [self performSelectorOnMainThread:@selector(mainThreadHandle:) withObject:data waitUntilDone:YES];

}

#pragma mark  回归主线程的一个更新UI的方法

-(void)mainThreadHandle:(NSData *)data{

    UIImage *imaged=[UIImage imageWithData:data];

    _image.image=imaged;

}

转载于:https://my.oschina.net/6104zhang/blog/745203