iOS多线程开发小demo5 线程间的通信

//  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