在ios程序沙盒中Documents下创建文件夹

NSFileManager *fileManager = [[NSFileManager alloc] init];    NSString *pathDocuments = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];    NSString *createPath = [NSString stringWithFormat:@"%@/Image", pathDocuments];    NSString *createDir = [NSString stringWithFormat:@"%@/MessageQueueImage", pathDocuments];    // 判断文件夹是否存在，如果不存在，则创建    if (![[NSFileManager defaultManager] fileExistsAtPath:createPath]) {        [fileManager createDirectoryAtPath:createPath withIntermediateDirectories:YES attributes:nil error:nil];        [fileManager createDirectoryAtPath:createDir withIntermediateDirectories:YES attributes:nil error:nil];    } else {        NSLog(@"FileDir is exists.");    }