- (NSInteger)fileSize{

     //文件管理者

     NSFileManager *mgr = [NSFileManager defaultManager];

     //判断字符串是否为文件/文件夹

     BOOL dir = NO;

     BOOL exists = [mgr fileExistsAtPath:self isDirctory:&dir];

     //文件/文件夹不存在

     if (exists == NO) return ;

     //self是文件夹

     if (dir){

          //遍历文件夹中的所有内容

          NSArray *subpaths = [mgr subpathsAtPath:self];

          //计算文件夹大小

          NSInteger totalByteSize = ;

          for (NSString *subpath in subpaths){

               //拼接全路径

                NSString *fullSubPath = [self stringByAppendingPathComponent:subpath];

             //判断是否为文件

             BOOL dir = NO;

             [mgr fileExistsAtPath:fullSubPath isDirectory:&dir];

             if (dir == NO){//是文件

                    NSDictionary *attr = [mgr attributesOffItemAtPath:fullSubPath error:ni];

                    totalByteSize += [attr[NSFileSize] integerValue];

              }

          }

          return totalByteSize;

     } else{//是文件

           NSDictionary *attr = [mgr attributesOffItemAtPath:self error:ni];

            return [attr[NSFileSize] integerValue];

    }

 }    

 NSString *caches =[[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];

 Integer cachesSize = [caches fileSize];