iOS线程间通信 - NSThread篇

线程间通信常用方法：

- (void)performSelectorOnMainThread:(SEL)aSelector withObject:(id)arg waitUntilDone:(BOOL)wait;

- (void)performSelector:(SEL)aSelector onThread:(NSThread *)thr withObject:(id)arg waitUntilDone:(BOOL)wait；

开子线程下载数据，在主线程刷新UI；

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
   //NSOperation 篇
//    [self downLoadImageAndShow];
//NSThread 篇
    [self performSelectorInBackground:@selector(downLoad) withObject:nil];
}

#pragma mark - //NSThread 篇
- (void)downLoad{
    NSURL * url = [NSURL URLWithString:@"https://zuoye2.xinkaoyun.com/awm/35/iOS_09060620200720110101.jpeg"];
    NSData * data = [NSData dataWithContentsOfURL:url];
    UIImage * image = [UIImage imageWithData:data];
    [self performSelectorOnMainThread:@selector(iconSetImage:) withObject:image waitUntilDone:NO];
   
}

- (void)iconSetImage:(UIImage *)image{
    self.iconImageView.image = image;
}