IOS中计算文件的大小

通常用于删除缓存的时，计算缓存大小
//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;
}
//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){
NSString* fileAbsolutePath = [folderPath stringByAppendingPathComponent:fileName];
folderSize += [self fileSizeAtPath:fileAbsolutePath];
}
return folderSize/(1024.0*1024.0);
}