AFNetworking 图片的本地缓存问题

来源：互联网发布：淘宝蓝钻是什么意思编辑：程序博客网时间：2024/05/21 03:25

ASI好久没更新，于是今天试了下AFNetWorking，调用图片请求方法很方便

　   [self.imageViewsetImageWithURL:[NSURLURLWithString:@"http://best50.cn:8080/update/10/food/72.jpg"] placeholderImage:[UIImageimageNamed:@"placeholder.png"]];

但发现个问题，程序重新启动后，图片还要重新请求，原来AFN用的是内存缓存图片机制，这能提高程序效率，但我们有时候，图片的本地缓存也是很重要的，于是，对AFN下UIImageView+AFNetworking.m文件的代码进行了修改，欢迎大家进行指正，修改和添加的方法如下：

  1 - (void)setImageWithURLRequest:(NSURLRequest *)urlRequest   2               placeholderImage:(UIImage *)placeholderImage   3                        success:(void (^)(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image))success  4                        failure:(void (^)(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error))failure  5 {  6     [self cancelImageRequestOperation];  7   8       9     UIImage *cachedImage = [[[self class] af_sharedImageCache] cachedImageForRequest:urlRequest]; 10     if (cachedImage) { 11  12         self.image = cachedImage; 13         self.af_imageRequestOperation = nil; 14          15         if (success) { 16             success(nil, nil, cachedImage); 17         } 18     } else { 19         NSString *urlString = [[urlRequest URL] absoluteString]; 20         NSData *data = [self loadImageData:[self pathInCacheDirectory:@"WendaleCache"] imageName:[urlString md5]]; 21         if (data) { 22             self.image = [UIImage imageWithData:data]; 23             self.af_imageRequestOperation = nil; 24              25             if (success) { 26                 success(nil, nil, self.image); 27             } 28             return; 29         } 30          31         self.image = placeholderImage; 32          33         AFImageRequestOperation *requestOperation = [[AFImageRequestOperation alloc] initWithRequest:urlRequest]; 34         [requestOperation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) { 35             if ([[urlRequest URL] isEqual:[[self.af_imageRequestOperation request] URL]]) { 36                 if (success) { 37                     success(operation.request, operation.response, responseObject); 38                 }else if (responseObject) {

 39                 self.image = responseObject;}

 40                     //图片本地缓存 41                 if ([self createDirInCache:@"WendaleCache"]) { 42                     NSString *imageType = @"jpg"; 43                      //从url中获取图片类型 44                 　　NSMutableArray *arr = (NSMutableArray *)[urlString componentsSeparatedByString:@"."]; 45                     if (arr) { 46                          imageType = [arr objectAtIndex:arr.count-1]; 47                      } 48                      [self saveImageToCacheDir:[self pathInCacheDirectory:@"WendaleCache"] image: responseObject imageName:[urlString md5] imageType:imageType]; 49                 } 50                      51                      52  53                  54                 self.af_imageRequestOperation = nil; 55             } 56  57             [[[self class] af_sharedImageCache] cacheImage:responseObject forRequest:urlRequest]; 58  59         } failure:^(AFHTTPRequestOperation *operation, NSError *error) { 60             if ([[urlRequest URL] isEqual:[[self.af_imageRequestOperation request] URL]]) { 61                 if (failure) { 62                     failure(operation.request, operation.response, error); 63                 } 64                  65                 self.af_imageRequestOperation = nil; 66             } 67         }]; 68          69         self.af_imageRequestOperation = requestOperation; 70          71         [[[self class] af_sharedImageRequestOperationQueue] addOperation:self.af_imageRequestOperation]; 72     } 73 } 74  75 -(NSString* )pathInCacheDirectory:(NSString *)fileName 76 { 77     NSArray *cachePaths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES); 78     NSString *cachePath = [cachePaths objectAtIndex:0]; 79     return [cachePath stringByAppendingPathComponent:fileName]; 80 } 81 //创建缓存文件夹 82 -(BOOL) createDirInCache:(NSString *)dirName 83 { 84     NSString *imageDir = [self pathInCacheDirectory:dirName]; 85     BOOL isDir = NO; 86     NSFileManager *fileManager = [NSFileManager defaultManager]; 87     BOOL existed = [fileManager fileExistsAtPath:imageDir isDirectory:&isDir]; 88     BOOL isCreated = NO; 89     if ( !(isDir == YES && existed == YES) ) 90     { 91         isCreated = [fileManager createDirectoryAtPath:imageDir withIntermediateDirectories:YES attributes:nil error:nil]; 92     } 93     if (existed) { 94         isCreated = YES; 95     } 96     return isCreated; 97 } 98  99 // 删除图片缓存100 - (BOOL) deleteDirInCache:(NSString *)dirName101 {102     NSString *imageDir = [self pathInCacheDirectory:dirName];103     BOOL isDir = NO;104     NSFileManager *fileManager = [NSFileManager defaultManager];105     BOOL existed = [fileManager fileExistsAtPath:imageDir isDirectory:&isDir];106     bool isDeleted = false;107     if ( isDir == YES && existed == YES )108     {109         isDeleted = [fileManager removeItemAtPath:imageDir error:nil];110     }111     112     return isDeleted;113 }114 115 // 图片本地缓存116 - (BOOL) saveImageToCacheDir:(NSString *)directoryPath  image:(UIImage *)image imageName:(NSString *)imageName imageType:(NSString *)imageType117 {118     BOOL isDir = NO;119     NSFileManager *fileManager = [NSFileManager defaultManager];120     BOOL existed = [fileManager fileExistsAtPath:directoryPath isDirectory:&isDir];121     bool isSaved = false;122     if ( isDir == YES && existed == YES )123     {124         if ([[imageType lowercaseString] isEqualToString:@"png"])125         {126             isSaved = [UIImagePNGRepresentation(image) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"png"]] options:NSAtomicWrite error:nil];127         }128         else if ([[imageType lowercaseString] isEqualToString:@"jpg"] || [[imageType lowercaseString] isEqualToString:@"jpeg"])129         {130             isSaved = [UIImageJPEGRepresentation(image, 1.0) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"jpg"]] options:NSAtomicWrite error:nil];131         }132         else133         {134             NSLog(@"Image Save Failed\nExtension: (%@) is not recognized, use (PNG/JPG)", imageType);135         }136     }137     return isSaved;138 }139 // 获取缓存图片140 -(NSData*) loadImageData:(NSString *)directoryPath imageName:( NSString *)imageName141 {142     BOOL isDir = NO;143     NSFileManager *fileManager = [NSFileManager defaultManager];144     BOOL dirExisted = [fileManager fileExistsAtPath:directoryPath isDirectory:&isDir];145     if ( isDir == YES && dirExisted == YES )146     {147         NSString *imagePath = [directoryPath stringByAppendingString : imageName];148         BOOL fileExisted = [fileManager fileExistsAtPath:imagePath];149         if (!fileExisted) {150             return NULL;151         }152         NSData *imageData = [NSData dataWithContentsOfFile : imagePath];153         return imageData;154     }155     else156     {157         return NULL;158     }159 }