ios中asihttprequest 下载缓存

#import <UIKit/UIKit.h>
#import "ASIHTTPRequest.h"
#import "ASIDownloadCache.h"
@interface ViewController : UIViewController<ASIHTTPRequestDelegate>
- (IBAction)click:(id)sender;
@property (retain, nonatomic) IBOutlet UIImageView *img1;

@end

#import "ViewController.h"

@interface ViewController ()
{

}
@property(nonatomic,retain)NSDate *startData;
@property(nonatomic,retain)NSDate *endData;
@end

@implementation ViewController

- (void)viewDidLoad
{
[super viewDidLoad];

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

- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

- (IBAction)click:(id)sender {

[self download];

}

-(void)download{
self.startData=[NSDate date];
NSLog(@"start-->%@",self.startData);
__block ASIHTTPRequest *request=nil;
NSString *url=@"http://d.hiphotos.baidu.com/album/w%3D2048/sign=349954701b4c510faec4e51a5461272d/d1a20cf431adcbefc5d4f4beadaf2edda2cc9fa2.jpg";
request=[ASIHTTPRequest requestWithURL:[NSURL URLWithString:url]];
request.delegate=self;
//设置缓存时间
request.secondsToCache=24*60*60*7;//一周

NSString *cachePath=[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
cachePath =[cachePath stringByAppendingPathComponent:@"res"];
//缓存类
ASIDownloadCache *_cache=[ASIDownloadCache sharedCache];

[request setCacheStoragePolicy:ASICachePermanentlyCacheStoragePolicy];
[request setDownloadCache:_cache];
[request setCachePolicy:ASIOnlyLoadIfNotCachedCachePolicy];
[request startAsynchronous];

}

-(void)success:(ASIHTTPRequest *)request{
if ([request didUseCachedResponse]) {
NSLog(@"来自于缓存");
}
else{
NSLog(@"NO");
}
}

-(void)requestFinished:(ASIHTTPRequest *)request{
if ([request didUseCachedResponse]) {
self.endData=[NSDate date];
NSLog(@"来缓存-->%@",self.endData);
self.img1.image=[UIImage imageWithData:[request responseData]];
}
else{
self.endData=[NSDate date];

NSLog(@"   NO-->%@",self.endData);
self.img1.image=[UIImage imageWithData:[request responseData]];
}
}

-(void)requestFailed:(ASIHTTPRequest *)request{

}

- (void)dealloc {
[_img1 release];
[self.startData release];
[self.endData release];
[super dealloc];
}
@end

-(void)download{
__block ASIHTTPRequest *request=nil;

NSString *url=@"http://f.hiphotos.baidu.com/album/w%3D2048/sign=288b34a9e4dde711e7d244f693d7cc1b/18d8bc3eb13533fa7f621782a9d3fd1f40345b42.jpg";
request=[ASIHTTPRequest requestWithURL:[NSURL URLWithString:url]];
request.delegate=self;
//设置缓存时间
request.secondsToCache=24*60*60*7;//一周

//设置完成时回调方法
[request setDidFinishSelector:@selector(success:)];

NSString *cachePath=[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
cachePath =[cachePath stringByAppendingPathComponent:@"res"];
//缓存类
ASIDownloadCache *_cache=[ASIDownloadCache sharedCache];
//设置缓存目录
[_cache setStoragePath:cachePath];
//设置缓存策略
[_cache setDefaultCachePolicy:ASIOnlyLoadIfNotCachedCachePolicy];

//request永久存储
[request setCacheStoragePolicy:ASICachePermanentlyCacheStoragePolicy];
[request setDownloadCache:_cache];

[request startAsynchronous];
}

-(void)success:(ASIHTTPRequest *)request{
if ([request didUseCachedResponse]) {
NSLog(@"来自于缓存");
}
else{
NSLog(@"NO");
}
}

-(void)requestFailed:(ASIHTTPRequest *)request{

}