Question

我使用网络服务，我得到服务的回复。回应将有不同的结构。例如，API getInfo返回响应：

{"code":0,"message":"","result":{"nickname":"UserName","age":"22"}}

API登录：

{"code":0,"message":"","result":"user_token"}

等。我使用HttpWebRequest作为POST请求。请求和响应使用DataContractSerializer反序列化/序列化。

所以，我想使用工厂模式，这是我的实现：

[DataContract]
public class ResultGetInfo
{
    [DataMember(Name = "nickname")]
    public int Nickname { get; set; }
    [DataMember(Name = "age")]
    public int Age { get; set; }
}

[DataContract]
public abstract class Response
{
}

[DataContract]
public class ResponseSignin : Response
{
    [DataMember(Name = "code")]
    public int Code { get; set; }
    [DataMember(Name = "message")]
    public string Message { get; set; }
    [DataMember(Name = "result")]
    public string Result { get; set; }
}

[DataContract]
public class ResponseGetInfo : Response
{
    [DataMember(Name = "code")]
    public int Code { get; set; }
    [DataMember(Name = "message")]
    public string Message { get; set; }
    [DataMember(Name = "result")]
    public ResultGetInfo Result { get; set; }
}

public abstract class CreateResponse
{
    public abstract Response CreateResponseObj();
}

public class CreateResponseSignin : CreateResponse
{
    public override Response CreateResponseObj()
    {
        return new ResponseSignin();
    }
}

public class CreateResponseGetInfo : CreateResponse
{
    public override Response CreateResponseObj()
    {
        return new ResponseGetInfo();
    }
}

我在回调函数中获得响应：

private void getResponseCallback(IAsyncResult asynchronousResult)
{
    var request = (Request)asynchronousResult.AsyncState;
    try
    {
        HttpWebResponse response;

        // End the get response operation
        response = (HttpWebResponse)request.HttpRequest.EndGetResponse(asynchronousResult);
        Stream streamResponse = response.GetResponseStream();
        StreamReader streamReader = new StreamReader(streamResponse);
        var gyResponse = streamReader.ReadToEnd();
        streamResponse.Close();
        streamReader.Close();
        response.Close();
        Response response_obj = request.Creater.CreateResponseObj();  

        using (MemoryStream stream = new MemoryStream(Encoding.Unicode.GetBytes(gyResponse)))
        {
            var serializer = new DataContractJsonSerializer(response_obj.GetType());                                     
            response_obj = (Response)serializer.ReadObject(stream);
            if (request.CallBack != null)
            {
                request.CallBack.Invoke(response_obj, null);
            }
        }
    }
    catch (WebException e)
    {
        if (request.CallBack != null)
        {
            request.CallBack.Invoke(null, e);
        }
    }
}

对于DataContractJsonSerializer我在此声明类型：

var serializer = new DataContractJsonSerializer(response_obj.GetType());

其中response_obj是对象，需要类型（ResponseSignin或ResponseGetInfo）。

所以，我在我的代表中致电Invoke()。

private void ResponseHandler(Response result, Exception error)
{
    if (error != null)
    {
        string err = error.Message;
    }
    else
    {
        Response response = result;
    }
}

这里我有一个问题。变量result确实包含正确答案，但我没有得到属性，因为抽象类Response没有属性。我不能在派生类中声明属性或覆盖。我不确定是否选择了所需的模式。

Answer 1

您是否尝试过将result变量转换为您需要的类型？

E.g。

private void ResponseHandler(Response result, Exception error)
{
    if (error != null)
    {
        string err = error.Message;
        return;
    }

    var signInResponse = result as ResponseSignin;
    if (signInResponse != null)
    {
        HandleSignInResponse(signInResponse);
    }

    var infoResponse = result as ResponseGetInfo;
    if (infoResponse != null)
    {
        HandleInfoResponse(infoResponse);
    }
}

实施工厂模式的问题

1 个答案: