iOS中在沙盒中创建指定文件夹

    //获取Document文件
    NSString * docsdir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSString * rarFilePath = [docsdir stringByAppendingPathComponent:@"Announcement"];//将需要创建的串拼接到后面
    NSString * dataFilePath = [docsdir stringByAppendingPathComponent:@"AnnouncementData"];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    BOOL isDir = NO;
    BOOL dataIsDir = NO;
    // fileExistsAtPath 判断一个文件或目录是否有效，isDirectory判断是否一个目录
    BOOL existed = [fileManager fileExistsAtPath:rarFilePath isDirectory:&isDir];
    BOOL dataExisted = [fileManager fileExistsAtPath:dataFilePath isDirectory:&dataIsDir];
    if ( !(isDir == YES && existed == YES) ) {//如果文件夹不存在
        [fileManager createDirectoryAtPath:rarFilePath withIntermediateDirectories:YES attributes:nil error:nil];
    }
    if (!(dataIsDir == YES && dataExisted == YES) ) {
        [fileManager createDirectoryAtPath:dataFilePath withIntermediateDirectories:YES attributes:nil error:nil];
    }