wcf - WCF コールバック生成インターフェイス

Question

.NET フレームワーク 3.5。サーバー側にはインターフェースがあります

public interface IClientCallback
{
    [OperationContract(IsOneWay = true)]
    void ReceiveBroadcast(string nickname, string message);

    [OperationContract(IsOneWay = true)]
    void ReceivePrivate(string nickname, string message);

    [OperationContract(IsOneWay = true)]
    void UserJoined(string nickname);

    [OperationContract(IsOneWay = true)]
    void UserLeft(string nickname);
}

svcutil を使用すると、次のインターフェイスが生成されます

public interface IServerCallback
{

    [System.ServiceModel.OperationContractAttribute(IsOneWay=true, Action="http://tempuri.org/IServer/ReceiveBroadcast")]
    void ReceiveBroadcast(string nickname, string message);

    [System.ServiceModel.OperationContractAttribute(IsOneWay=true, AsyncPattern=true, Action="http://tempuri.org/IServer/ReceiveBroadcast")]
    System.IAsyncResult BeginReceiveBroadcast(string nickname, string message, System.AsyncCallback callback, object asyncState);

    void EndReceiveBroadcast(System.IAsyncResult result);

    [System.ServiceModel.OperationContractAttribute(IsOneWay=true, Action="http://tempuri.org/IServer/ReceivePrivate")]
    void ReceivePrivate(string nickname, string message);

    [System.ServiceModel.OperationContractAttribute(IsOneWay=true, AsyncPattern=true, Action="http://tempuri.org/IServer/ReceivePrivate")]
    System.IAsyncResult BeginReceivePrivate(string nickname, string message, System.AsyncCallback callback, object asyncState);

    void EndReceivePrivate(System.IAsyncResult result);

    [System.ServiceModel.OperationContractAttribute(IsOneWay=true, Action="http://tempuri.org/IServer/UserJoined")]
    void UserJoined(string nickname);

    [System.ServiceModel.OperationContractAttribute(IsOneWay=true, AsyncPattern=true, Action="http://tempuri.org/IServer/UserJoined")]
    System.IAsyncResult BeginUserJoined(string nickname, System.AsyncCallback callback, object asyncState);

    void EndUserJoined(System.IAsyncResult result);

    [System.ServiceModel.OperationContractAttribute(IsOneWay=true, Action="http://tempuri.org/IServer/UserLeft")]
    void UserLeft(string nickname);

    [System.ServiceModel.OperationContractAttribute(IsOneWay=true, AsyncPattern=true, Action="http://tempuri.org/IServer/UserLeft")]
    System.IAsyncResult BeginUserLeft(string nickname, System.AsyncCallback callback, object asyncState);

    void EndUserLeft(System.IAsyncResult result);
}

ご覧のとおり、すべての操作は一方向ですが、End* および Begin* メソッドを提供します。原因は何ですか？AsyncPattern = false を IClientCallback メソッドに追加しようとしましたが、結果はありませんでした。