C#でWebAPI叩いてJson形式の結果を受け取る処理メモ

※C#初心者なのでメモです

環境

• .NET Framework 3.5

4.0 からはDynamicJSONが使えるらしい

using追加

using System.IO;
using System.Net;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Json;
using System.Web.Script.Serialization

データコントラクト定義

[DataContract]
public class RequestResult
{
    [DataMember]
    public string data1 { get; set; }
    [DataMember]
    public string data2 { get; set; }
    [DataMember]
    public string data3 { get; set; }
    [DataMember]
    public string data4 { get; set; }
}

実処理

    HttpWebRequest req = (HttpWebRequest)WebRequest.Create("http://example.com/api/hoge");
    req.ContentType = "application/json";
    req.Method = "POST";

    using (var streamWriter = new StreamWriter(req.GetRequestStream()))
    {
        string jsonPayload = new JavaScriptSerializer().Serialize(new
        {
            hoge = "APIを",
            piyo = "叩く際に渡す",
            foo = "パラメータ"
        });
        streamWriter.Write(jsonPayload);
    }

    HttpWebResponse res = (HttpWebResponse)req.GetResponse();
    RequestResult result;
    using (res)
    {
        using (var resStream = res.GetResponseStream())
        {
            var serializer = new DataContractJsonSerializer(typeof(RequestResult));
            result = (RequestResult)serializer.ReadObject(resStream);
        }
    }

参考

• http://stackoverflow.com/questions/9145667/how-to-post-json-to-the-server
• https://msdn.microsoft.com/ja-jp/library/bb412179(v=vs.90).aspx
• https://msdn.microsoft.com/ja-jp/library/cc668800(v=vs.90).aspx
• https://msdn.microsoft.com/ja-jp/library/system.io.streamwriter(v=vs.110).aspx
• https://msdn.microsoft.com/ja-jp/library/system.net.httpwebresponse.getresponsestream(v=vs.110).aspx
• http://posnum.hatenablog.com/entry/2014/09/19/233255
• http://www.sonnagaya.com/entry/20140704/1404434783
• http://argius.hatenablog.jp/entry/20131113/1384352397