# 设置事件通知
![](https://support.huaweicloud.com/sdk-dotnet-devg-obs/public_sys-resources/notice_3.0-zh-cn.png)
开发过程中，您有任何问题可以在github上[提交issue](https://github.com/huaweicloud/huaweicloud-sdk-dotnet-obs/issues)，或者在[华为云对象存储服务论坛](https://bbs.huaweicloud.com/forum/forum-620-1.html)中发帖求助。[接口参考文档](https://obssdk.obs.cn-north-1.myhuaweicloud.com/apidoc/cn/dotnet/html/G_OBS.htm)详细介绍了每个接口的参数和使用方法。
您可以通过ObsClient.SetBucketNotification设置桶的事件通知。在该操作前，需要在消息通知服务SMN[创建主题](https://support.huaweicloud.com/usermanual-smn/zh-cn_topic_0043961401.html)，并[设置主题策略](https://support.huaweicloud.com/usermanual-smn/zh-cn_topic_0043394891.html)为OBS。
以下代码展示了如何设置桶的事件通知：
```
// 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.html
string 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);
// 设置事件通知
try
{
    FilterRule filterRule1 = new FilterRule();
    filterRule1.Name = FilterNameEnum.Prefix;
    filterRule1.Value = "smn";
    TopicConfiguration topicConfiguration1 = new TopicConfiguration();
    topicConfiguration1.Id = "Id001";
    // 设置主题URN，需要在消息通知服务（SMN）创建主题，示例：urn:smn:region:xxx:topicName
    topicConfiguration1.Topic = "your topic1 URN";
    topicConfiguration1.Events.Add(EventTypeEnum.ObjectCreatedAll);
    topicConfiguration1.FilterRules.Add(filterRule1);
    FilterRule filterRule2 = new FilterRule();
    filterRule2.Name = FilterNameEnum.Suffix;
    filterRule2.Value = ".jpg";
    TopicConfiguration topicConfiguration2 = new TopicConfiguration();
    topicConfiguration2.Id = "Id002";
    topicConfiguration2.Topic = "your topic2 URN";
    topicConfiguration2.Events.Add(EventTypeEnum.ObjectCreatedAll);
    topicConfiguration2.FilterRules.Add(filterRule2);
    NotificationConfiguration notificationConfiguration = new NotificationConfiguration();
    notificationConfiguration.TopicConfigurations.Add(topicConfiguration1);
    notificationConfiguration.TopicConfigurations.Add(topicConfiguration2);
    SetBucketNotificationRequest request = new SetBucketNotificationRequest
    {
        BucketName = "bucketname",
        Configuration = notificationConfiguration,
    };
    SetBucketNotificationResponse response = client.SetBucketNotification(request);
    Console.WriteLine("Set bucket notification response: {0}", response.StatusCode);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
}
```