获取iOS文件夹大小（空间占用）

+ (float)calculateFileSizeInUnit:(unsigned long long)contentLength

{

    if(contentLength >= pow(1024, 3))

        return (float) (contentLength / (float)pow(1024, 3));

    else if(contentLength >= pow(1024, 2))

        return (float) (contentLength / (float)pow(1024, 2));

    else if(contentLength >= 1024)

        return (float) (contentLength / (float)1024);

    else

        return (float) (contentLength);

}

+ (NSString *)calculateUnit:(unsigned long long)contentLength

{

    if(contentLength >= pow(1024, 3))

        return @"GB";

    else if(contentLength >= pow(1024, 2))

        return @"MB";

    else if(contentLength >= 1024)

        return @"KB";

    else

        return @"Bytes";

}

+ (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;

}

+ (long long) fileSizeAtPath:(NSString*) filePath{

    NSFileManager* manager = [NSFileManager defaultManager];

    if ([manager fileExistsAtPath:filePath]){

        return [[manager attributesOfItemAtPath:filePath error:nil] fileSize];

    }

    return 0;

}



+(NSString *)folderSizeStringAtPath:(NSString*) filePath

{

    float size=[self folderSizeAtPath:filePath];

    NSString *fileSizeString=[NSString stringWithFormat:@"%.02f%@",[self calculateFileSizeInUnit:size],[self calculateUnit:size]];

    return fileSizeString;

}