如何使用'POST'方法使用c＃获取JSON数据？

Question

我想请求一组特定的从BLS网站的数据：

http://www.bls.gov/developers/api_signature_v2.htm#parameters

该链接，我特别想获得一个系列可选参数。我超级接近，但它就好像我的JSON发布请求没有被处理。

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 
using System.Threading.Tasks; 
using System.Windows; 
using System.Net; 
using System.Data.SqlClient; 
using System.Web; 
using System.Configuration; 
using System.Data; 
using System.Globalization; 
using System.ComponentModel; 
using Newtonsoft.Json; 
using System.Web.Script.Serialization; 
using System.IO; 
using System.Net.Http; 
using System.Net.Http.Headers; 



namespace ConsoleApplication5 
{ 


//Classes needed to deserialze JSON data (JSON to C# website) 
public class DataObject 
{ 
    public string Name { get; set; } 
} 

public class Footnote 
{ 
} 

public class Datum 
{ 
    public string year { get; set; } 
    public string period { get; set; } 
    public string periodName { get; set; } 
    public string value { get; set; } 
    public List<Footnote> footnotes { get; set; } 

} 

public class Series 
{ 
    public string seriesID { get; set; } 
    public List<Datum> data { get; set; } 


} 

public class Results 
{ 
    public List<Series> series { get; set; } 
} 

public class RootObject 
{ 
    public string status { get; set; } 
    public int responseTime { get; set; } 
    public List<object> message { get; set; } 
    public Results Results { get; set; } 

    public override string ToString() 
    { 
     return string.Format("Status: {0}", status); 
    } 

} 

class Program 
{ 

    static double octLY; 
    static double oct2y; 

    static void Main(string[] args) 
    { 
     TryParsing(); 

    } 


    static void TryParsing() 
    { 
     var httpWebRequest = (HttpWebRequest)WebRequest.Create("http://api.bls.gov/publicAPI/v2/timeseries/data/CUUR0000SA0"); 
     httpWebRequest.ContentType = "application/json"; 
     httpWebRequest.Method = "POST"; 

     using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream())) 
     { 
      //string json = new JavaScriptSerializer().Serialize(new 
      //{ 
      // seriesid = "CUUR0000SA0", 
      // startYear = "2010", 
      // endYear = "2015", 
      // catalog = "true", 
      // calculations = "true", 
      // annualAverage = "true", 
      // registrationKey = "f3171173a8ce4b969b5085ba9a83202f" 


      //}); 

      string json = "{\"seriesid\":[\"CUUR0000SA0\"],\"startyear\":\"2010\",\"endyear\":\"2015\",\"catalog\":true,\"calculations\":true,\"annualAverage\":true,\"registrationKey\":\"f3171173a8ce4b969b5085ba9a83202f\"}"; 

      //Console.WriteLine(json.ToString()); 
      //Console.ReadLine(); 

      streamWriter.Write(json); 
      streamWriter.Flush(); 
      streamWriter.Close(); 
     } 

     var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse(); 
     using (var streamReader = new StreamReader(httpResponse.GetResponseStream())) 
      { 
      var result = streamReader.ReadToEnd(); 
      Console.WriteLine(result.ToString()); 
      Console.ReadLine(); 
      } 
     } 

    } 
} 

我在JSON发布数据中进行了硬编码，以便完全符合BLS链接上的示例。问题是它忽略了我所有的参数。虽然要求5等，但我只获得3年的数据...

使用我的授权码是很好的，因为这是通用的，稍后会更改。

有人可以告诉我如何使用POST方法请求这些数据吗？我觉得我只是想念一些基本的东西，但无法得到它。如果你重新创建这个问题，它会很容易，因为它是所有的开源数据等等......但由于它没有在请求中看到我的授权，它每天限制用户25个请求。 ..所以如果你运行这个26倍......你会得到一个超出请求的消息。如果这得到工作，从25倍变为500

这里是我的其他的方法，我是想：

static void TryParse() 
    { 
     //Get JSON data 
     using (WebClient wc = new WebClient()) 
     { 
      var json = wc.DownloadString("http://api.bls.gov/publicAPI/v2/timeseries/data/CUUR0000SA0"); 

      //Deserialize JSON data 
      var p1 = new JavaScriptSerializer(); 
      RootObject j = p1.Deserialize<RootObject>(json); 

      RootObject r1 = JsonConvert.DeserializeObject<RootObject>(json); 


      //check to see if JSON data was successfully downloaded 
      if (r1.ToString() == "Status: REQUEST_SUCCEEDED") 
      { 

       //Loop through the JSON to find values 
       foreach (Datum d in j.Results.series[0].data) 
       { 
        //Filters data based on year value 
        if ((Int16.Parse(d.year) == DateTime.Now.Year - 1 && d.period == "M10")) //|| (Int16.Parse(d.year) == DateTime.Now.Year - 1 && d.period == "M10"))) 
        { 
         octLY = (double.Parse(d.value)); 
         Console.WriteLine("OCT14: {0}", octLY); 

         //Console.WriteLine(d.year + " : " + d.period + " : " + d.periodName + " : " + d.value); 
        } 

        if (Int16.Parse(d.year) == DateTime.Now.Year - 2 && d.period == "M10") 
        { 
         oct2y = (double.Parse(d.value)); 
         Console.WriteLine("OCT13: {0}", oct2y); 

        } 
        else { } 
       } 

       Console.WriteLine("CPI: {0}", (octLY - oct2y)/oct2y + 1); 
      } 

      else 
      { 
       Console.WriteLine(r1.ToString()); 
       Console.ReadLine(); 
      } 


      Console.ReadLine(); 
     } 

    } 

Answer 1

使用你的代码，我能够在我的RootObject类结果取回有效的数据重新创建。系列集合。首先我创建了一个新的Class Called Series Post。

public class SeriesPost 
{ 
    public string[] seriesid { get; set; } 
    public string startyear { get; set; } 
    public string endyear { get; set; } 
    public bool catalog { get; set; } 
    public bool calculations { get; set; } 
    public bool annualaverage { get; set; } 
    public string registrationKey { get; set; } 
} 

从那里我修改你的JSON serilalization有点

using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream())) 
{ 
     string newJson = Newtonsoft.Json.JsonConvert.SerializeObject(new SeriesPost() 
     { 
      seriesid = (new List<string>() { "CUUR0000SA0" }).ToArray(), 
      startyear = "2010", 
      endyear = "2015", 
      catalog = false, 
      calculations = true, 
      annualaverage = true, 
      registrationKey = "f3171173a8ce4b969b5085ba9a83202f" 

     }); 
     //So you can see the JSON thats output 
     System.Diagnostics.Debug.WriteLine(newJson); 
     streamWriter.Write(newJson); 
     streamWriter.Flush(); 
     streamWriter.Close(); 
    } 
var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse(); 
     using (var streamReader = new StreamReader(httpResponse.GetResponseStream())) 
     { 
      var result = streamReader.ReadToEnd(); 
      //Here your RootObject is the Type thats returned with your results 
      RootObject obj = Newtonsoft.Json.JsonConvert.DeserializeObject<RootObject>(result); 
      // Loop over the series in the results 
      foreach(Series ser in obj.Results.series) 
      { 
       // Loop over the Data in each of the series. 
       foreach(var data in ser.data) 
       { 
        //Output the year, in my test I got multiple entries for each year between 2010 to 2015 
        Console.WriteLine(data.year); 
       } 
      } 
      Console.ReadLine(); 
     }