iOS 08-线程通信

#import "ViewController.h"

#define IMAGE_URL @"https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1505384144967&di=c99009f5c44b8bca603bd3aef02726d5&imgtype=0&src=http%3A%2F%2Ftupian.enterdesk.com%2Fuploadfile%2F2012%2F1011%2F20121011092237493.jpg"

@interface ViewController ()

@property (weak,nonatomic) IBOutletUIImageView *imageView;

@end

@implementation ViewController

- (void)viewDidLoad {

    [superviewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.

}

- (void)didReceiveMemoryWarning {

    [superdidReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {

   

    [NSThreaddetachNewThreadSelector:@selector(downLoadImage)toTarget:selfwithObject:nil];

}

-(void)downLoadImage {

    NSURL *url = [NSURLURLWithString:IMAGE_URL];

    NSData *data = [NSDatadataWithContentsOfURL:url];

    UIImage *image = [UIImageimageWithData:data];

    

    //一、线程通信由子线程回归到主线程

//    [selfperformSelectorOnMainThread:@selector(loadImage:)withObject:image waitUntilDone:NO];

    //二、第二种方式

//    [selfperformSelector:@selector(loadImage:)onThread:[NSThreadmainThread] withObject:imagewaitUntilDone:NO];

    //三、第三种方式

    [self.imageViewperformSelectorOnMainThread:@selector(setImage:)withObject:image waitUntilDone:NO];

    

    NSLog(@"waitUntilDone:NO时才会先执行");

}

-(void)loadImage:(id)obj {

    self.imageView.image = obj;

}

@end

运行效果：