c# - 从我发送的 post 请求中读取我的 json 响应

Question

我创建了一个 post 请求类，我可以重复使用它来向外部 api 发出 POST 请求并返回它们发送给我的对象 (JSON):

class PostRequest
    {
        private Action<DataUpdateState> Callback;

        public PostRequest(string urlPath, string data, Action<DataUpdateState> callback)
        {
            Callback = callback;

            // form the URI
            UriBuilder fullUri = new UriBuilder(urlPath);
            fullUri.Query = data;

            // initialize a new WebRequest
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(fullUri.Uri);
            request.Method = "POST";

            // set up the state object for the async request
            DataUpdateState dataState = new DataUpdateState();
            dataState.AsyncRequest = request;

            // start the asynchronous request
            request.BeginGetResponse(new AsyncCallback(HandleResponse),
                dataState);
        }

        private void HandleResponse(IAsyncResult asyncResult)
        {
            // get the state information
            DataUpdateState dataState = (DataUpdateState)asyncResult.AsyncState;
            HttpWebRequest dataRequest = (HttpWebRequest)dataState.AsyncRequest;

            // end the async request
            dataState.AsyncResponse = (HttpWebResponse)dataRequest.EndGetResponse(asyncResult);
            if (dataState.AsyncResponse.StatusCode.ToString() == "OK")
            {
                Callback(dataState); // THIS IS THE LINE YOU SHOULD LOOK AT :)
            }
        }
    }

    public class DataUpdateState
    {
        public HttpWebRequest AsyncRequest { get; set; }
        public HttpWebResponse AsyncResponse { get; set; }
    }
}

回调方法获取数据状态对象并将其推送到此函数:

    public void LoadDashboard( DataUpdateState dataResponse )
    {
        Stream response = dataResponse.AsyncResponse.GetResponseStream();
        //Encoding encode = System.Text.Encoding.GetEncoding("utf-8");
        //StreamReader readStream = new StreamReader(response, encode);
        //readStream.Close();


        Deployment.Current.Dispatcher.BeginInvoke(() => {
            App.RootFrame.Navigate(new Uri("/Interface.xaml", UriKind.RelativeOrAbsolute));
        });
    }

我现在不确定如何获取从 API 发送给我的回复正文。它返回 json 格式，我需要能够将其映射到一个不错的 C# 类并使用它在手机上显示内容。

我找不到不使用 JSON.NET 的示例(它没有适用于 Windows Phone 8 的程序集)

---

这是我安装 HTTPClient 类时遇到的错误:

Attempting to resolve dependency 'Microsoft.Bcl (≥ 1.1.3)'.
Attempting to resolve dependency 'Microsoft.Bcl.Build (≥ 1.0.4)'.
Successfully installed 'Microsoft.Bcl.Build 1.0.10'.
Successfully installed 'Microsoft.Bcl 1.1.3'.
Successfully installed 'Microsoft.Net.Http 2.2.13'.
Successfully added 'Microsoft.Bcl.Build 1.0.10' to UnofficialPodio.
Executing script file ***\packages\Microsoft.Bcl.Build.1.0.10\tools\Install.ps1'.
This reference cannot be removed from the project because it is always referenced by the compiler.
This reference cannot be removed from the project because it is always referenced by the compiler.
This reference cannot be removed from the project because it is always referenced by the compiler.
This reference cannot be removed from the project because it is always referenced by the compiler.
Executing script file ***\packages\Microsoft.Bcl.Build.1.0.10\tools\Uninstall.ps1'.
Successfully uninstalled 'Microsoft.Bcl 1.1.3'.
Successfully uninstalled 'Microsoft.Bcl.Build 1.0.10'.
Install failed. Rolling back...
Failed to add reference to 'System.IO'.

---

"{
    \"access_token\": \"123803120312912j\",
    \"token_type\": \"bearer\",
    \"ref\": {
        \"type\": \"user\",
        \"id\": 123123
    },
    \"expires_in\": 28800,
    \"refresh_token\": \"234234f23f423q432f\"
}"

...

public class Auth
{

    [DataMember(Name = "access_token")]  
    public string AccessToken { get; set; }

    [DataMember(Name = "token_type")]  
    public string TokenType { get; set; }

    [DataMember(Name = "expires_in")]  
    public string ExpiresIn { get; set; }

    [DataMember(Name = "refresh_token")]  
    public string RefreshToken { get; set; }

    //[DataMember(Name = "ref")]  
    //public string Ref { get; set; }

}

Answer 1

要获取响应数据，您需要在 HttpWebResponse 对象上调用 GetResponseStream()，然后从流中读取。像这样的事情:

using (Stream s = response.GetResponseStream())
{
    using (TextReader textReader = new StreamReader(s, true))
    {
        jsonString = textReader.ReadToEnd();
    }
}

要从 json 字符串中获取数据，您需要创建一个数据契约类来描述 json 数据，如下所示:

    [DataContract]
    public class ApiData
    {
        [DataMember(Name = "name")]  <--this name must be the exact name of the json key
        public string Name { get; set; }

        [DataMember(Name = "description")]
        public string Description { get; set; }
    }

接下来您可以从字符串反序列化 json 对象:

        using (MemoryStream stream = new MemoryStream(Encoding.UTF8.GetBytes(jsonString)))
        {
            DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(ApiData));
            ApiData obj = (ApiData)serializer.ReadObject(stream);
            return obj;
        }

WebRequest 可以正常工作，但我建议为 HttpClient 类安装 NuGet 包。它让生活变得更加简单。例如，您只需几行即可生成上述请求代码:

        HttpClient httpClient = new HttpClient();
        HttpRequestMessage msg = new HttpRequestMessage(new HttpMethod("POST"), escapedUrl);
        HttpResponseMessage response = await httpClient.SendAsync(msg);

在回答下面的问题时，这是我使用的通用 json 转换器代码:

public static class JsonHelper
{
    public static T Deserialize<T>(string json)
    {
        using (MemoryStream stream = new MemoryStream(Encoding.UTF8.GetBytes(json)))
        {
            DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(T));
            T obj = (T)serializer.ReadObject(stream);
            return obj;
        }
    }

    public static string Serialize(object objectToSerialize)
    {
        using (MemoryStream ms = new MemoryStream())
        {
            DataContractJsonSerializer serializer = new DataContractJsonSerializer(objectToSerialize.GetType());
            serializer.WriteObject(ms, objectToSerialize);
            ms.Position = 0;
            using (StreamReader sr = new StreamReader(ms))
            {
                return sr.ReadToEnd();
            }
        }
    }
}