多线程 线程之间的通信

//  DYFViewController.m

//  623-06-线程间的通信

//

//  Created by dyf on 14-6-23.

//  Copyright (c) 2014年 ___FULLUSERNAME___. All rights reserved.

//

 

#import "DYFViewController.h"

 

@interface DYFViewController ()

@property (weak, nonatomic) IBOutlet UIImageView *imaV;

 

@end

 

@implementation DYFViewController

 

- (void)viewDidLoad

{

    [super viewDidLoad];

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

}

 

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

{

    // 1.下载图片

    [self performSelector:@selector(download) withObject:nil];

     

    // 显示、刷新界面，只能在主界面

    // 2.显示图片

}

/**

 *  下载图片：子线程

 */

- (void)download

{

    // 1.根据URL下载图片

    NSURL *url = [NSURL URLWithString:@"http://image.cache.xiu8.com/live/125/125/997729.jpg"];

    NSLog(@"---------begin");

    NSData *data = [NSData dataWithContentsOfURL:url]; // 耗时

     

    NSLog(@"-----------end");

     

    UIImage *image = [UIImage imageWithData:data];

     

    // 2.回到主线程显示图片

//    [self.imaV performSelector:@selector(setImage:) onThread:[NSThread mainThread] withObject:image waitUntilDone:NO modes:nil];

    //[self performSelectorOnMainThread:@selector(settingImage:) withObject:nil waitUntilDone:NO];

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

}

/**

 *  显示图片：主线程

 *

 *  @param image image

 */

- (void)settingImage:(UIImage *)image

{

    self.imaV.image = image;

}

 

@end

 小结：主线程与子线程之间的通信