-( float )readCacheSize
{
NSString *cachePath = [NSSearchPathForDirectoriesInDomains (NSCachesDirectory , NSUserDomainMask , YES) firstObject];
return [ self folderSizeAtPath :cachePath];
}

// 遍历文件夹获得文件夹大小，返回多少 M
- ( float ) folderSizeAtPath:( NSString *) folderPath{
NSFileManager * manager = [NSFileManager defaultManager];
if (![manager fileExistsAtPath :folderPath]) return 0 ;
NSEnumerator *childFilesEnumerator = [[manager subpathsAtPath :folderPath] objectEnumerator];
NSString * fileName;
long long folderSize = 0 ;
while ((fileName = [childFilesEnumerator nextObject]) != nil ){
//获取文件全路径
NSString * fileAbsolutePath = [folderPath stringByAppendingPathComponent :fileName];
folderSize += [ self fileSizeAtPath :fileAbsolutePath];
}
return folderSize/( 1024.0 * 1024.0);
}
// 计算 单个文件的大小
- ( long long ) fileSizeAtPath:( NSString *) filePath{
NSFileManager * manager = [NSFileManager defaultManager];
if ([manager fileExistsAtPath :filePath]){
return [[manager attributesOfItemAtPath :filePath error : nil] fileSize];
}
return 0;
}

- (void)clearFile
{
NSString * cachePath = [NSSearchPathForDirectoriesInDomains (NSCachesDirectory , NSUserDomainMask , YES ) firstObject];
NSArray * files = [[NSFileManager defaultManager ] subpathsAtPath :cachePath];
//NSLog ( @"cachpath = %@" , cachePath);
for ( NSString * p in files) {
NSError * error = nil ;
//获取文件全路径
NSString * fileAbsolutePath = [cachePath stringByAppendingPathComponent :p];
if ([[NSFileManager defaultManager ] fileExistsAtPath :fileAbsolutePath]) {
[[NSFileManager defaultManager ] removeItemAtPath :fileAbsolutePath error :&error];
}
}
//读取缓存大小
float cacheSize = [self readCacheSize] *1024;
self.cacheSize.text = [NSString stringWithFormat:@"%.2fKB",cacheSize];
}