计算本地文件夹大小

- (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);
    
}


- (long long) fileSizeAtPath:(NSString*) filePath{
    
    NSFileManager* manager = [NSFileManager defaultManager];
    
    if ([manager fileExistsAtPath:filePath]){
        
        return [[manager attributesOfItemAtPath:filePath error:nil] fileSize];
    }
    return 0;
}