指定前缀列举

以下代码展示如何指定前缀列举对象：

// 初始化配置参数ObsConfig config = new ObsConfig();config.Endpoint = "https://your-endpoint";// 认证用的ak和sk硬编码到代码中或者明文存储都有很大的安全风险，建议在配置文件或者环境变量中密文存放，使用时解密，确保安全；本示例以ak和sk保存在环境变量中为例，运行本示例前请先在本地环境中设置环境变量AccessKeyID和SecretAccessKey。// 您可以登录访问管理控制台获取访问密钥AK/SK，获取方式请参见https://support.huaweicloud.com/usermanual-ca/ca_01_0003.htmlstring accessKey= Environment.GetEnvironmentVariable("AccessKeyID", EnvironmentVariableTarget.Machine);string secretKey= Environment.GetEnvironmentVariable("SecretAccessKey", EnvironmentVariableTarget.Machine);// 创建ObsClient实例ObsClient client = new ObsClient(accessKey, secretKey, config);// 指定前缀列举try{    ListObjectsRequest request = new ListObjectsRequest();    request.BucketName = "bucketname";    //指定前缀    request.Prefix = "prefix"; ;    ListObjectsResponse response = client.ListObjects(request);    foreach (ObsObject entry in response.ObsObjects)    {        Console.WriteLine("key = {0} size = {1}", entry.ObjectKey, entry.Size);    }}catch (ObsException ex){    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);}