tencent cloud

    // Setting message extension
    var list = new List<MessageExtension>
    {
      new MessageExtension
      {
        message_extension_key = "key",
        message_extension_value = "value"
      }
    };
    TIMResult res = TencentIMSDK.MsgSetMessageExtensions(message, list, (int code, string desc, List<MessageExtensionResult> results, string user_data)=>{
      // Async result of the message extension setting
    });

    // Get message extensions
    TIMResult res = TencentIMSDK.MsgGetMessageExtensions(message, (int code, string desc, List<MessageExtension> list, string user_data)=>{
      // Async result of the message extension getting
    });

    // Delete message extensions
    var list = new List<MessageExtension>
    {
      new MessageExtension
      {
        message_extension_key = "key",
        message_extension_value = "value"
      }
    };
    TIMResult res = TencentIMSDK.MsgDeleteMessageExtensions(message, list, (int code, string desc, List<MessageExtensionResult> results, string user_data)=>{
      // Async result of the message extension deletion
    });

    // Add an event listener for advanced messages
    TencentIMSDK.SetMsgExtensionsChangedCallback((string message_id, List<MessageExtension> message_extension_array, string user_data) => {
      // `message_extension_array` is the list of the modified message extension objects
    });
    TencentIMSDK.SetMsgExtensionsDeletedCallback((string message_id, List<MessageExtension> message_extension_array, string user_data) => {
      // `message_extension_array` is the list of the deleted message extension objects
    });