iOS多线程demo

//

//  rootView.m

//  testthread

//

//  Created by niuxinghua on 14-11-23.

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

//

#import "rootView.h"

@interface rootView ()

@end

@implementation rootView

- (instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil

{

   self = [superinitWithNibName:nibNameOrNil bundle:nibBundleOrNil];

   if (self) {

        // Custom initialization

    }

    return self;

}

- (void)viewDidLoad

{

    [superviewDidLoad];

    // Do any additional setup after loading the view.

   UIButton *button=[[UIButtonalloc]initWithFrame:CGRectMake(20,80, 40, 40)];

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

    button.tintColor=[UIColorredColor];

  _imageView=[[UIImageViewalloc]initWithFrame:CGRectMake(0,200, 100, 100)];

    [button addTarget:selfaction:@selector(download)forControlEvents:UIControlEventTouchUpInside];

    

        [self.viewaddSubview:_imageView];

    

//   [self.view setBackgroundColor:[UIColor redColor]];

    [self.viewaddSubview:button];

}

-(void)download{

    dispatch_async(dispatch_get_global_queue(0,0), ^{

        NSURL * url = [NSURLURLWithString:@"http://c.hiphotos.baidu.com/image/w%3D230/sign=89deac84cbea15ce41eee70a86013a25/55e736d12f2eb93811b5b8f3d7628535e4dd6fd3.jpg"];

       NSData * data = [[NSDataalloc]initWithContentsOfURL:url];

       UIImage *image = [[UIImagealloc]initWithData:data];

       if (data != nil) {

            dispatch_async(dispatch_get_main_queue(), ^{

               _imageView.image = image;

            });

        }

    });

}

- (void)didReceiveMemoryWarning

{

    [superdidReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}

/*

#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender

{

    // Get the new view controller using [segue destinationViewController].

    // Pass the selected object to the new view controller.

}

*/

@end

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