1. Dynamics 365 CRM online的WebAPI查询使用count=true生成下一个查询链接，实现分批查询超出5000记录的数据集

一、Dynamics 365 CRM online的WebAPI查询使用count=true生成下一个查询链接，实现分批查询超出5000记录的数据集

二、使用步骤

1.引入库

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net.Http;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System.Web;

2.直接贴上如下的测试成功的代码

 public HttpClient connectToCRM()
  {
        HttpClient httpClient = new HttpClient();
        System.Net.ServicePointManager.SecurityProtocol = System.Net.SecurityProtocolType.Tls12;
        AuthenticationContext authContext = new AuthenticationContext(tokenUrl, false);
        AuthenticationResult result = authContext.AcquireToken(resource, clientId, new UserCredential(username, pwd));

        httpClient.BaseAddress = new Uri(ServiceUrl);
        httpClient.Timeout = new TimeSpan(0, 2, 0);
        httpClient.DefaultRequestHeaders.Add("OData-MaxVersion", "4.0");
        httpClient.DefaultRequestHeaders.Add("OData-Version", "4.0");
        httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
        httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", result.AccessToken);

        httpClient.DefaultRequestHeaders.Add("Prefer", "odata.include-							                            annotations=\"Microsoft.Dynamics.CRM.fetchxmlpagingcookie\"");
        return httpClient;
  }


 public Task<HttpResponseMessage> getCRMData(string queryString, HttpClient httpClient, bool isNextLink = false)
 {
      Task<HttpResponseMessage> data = null;
      string OdataRequest = null;
      if (isNextLink)
      {
          OdataRequest = queryString;
      }
      else
      {
          OdataRequest = ServiceUrl + queryString;
      }
      try
      {
          //Task<System.IO.Stream> st = httpClient.GetStreamAsync(OdataRequest);
          data = httpClient.GetAsync(OdataRequest);
      }
      catch (Exception ex)
      {
          throw ex;
      }
      return data;
 }

 private string MetaDataQuerystring()
 {
 	string querystring = "salesorders?	 $select=salesorderid,thk_doc_no,invoice_no,datefulfilled,country,type,statecode,billto_country," +                                "&$expand=order_details($select=salesorderid,doc_no,productid,quantity,priceperunit),new_salesorder_salesperson($select=salespersonid)" +"&$filter=modifiedon ge '2020-11-11 0:00:00.000' and modifiedon lt '2020-11-11 13:59:59' &$orderby=modifiedon&$count=true ";

	return querystring;
}
public void getCrmJson()
{
  try
   {
       int pagingnumber = 1;
       int totalcount = 0;
       httpClient = crm.connectToCRM();
       bool hasNextLink = false;
       if (httpClient != null)
       {
           string curXml = this.MetaDataQuerystring();
           while (true)
           {
               JObject _jobj = new JObject();
               _jobj = crm.convertToJson(crm.getCRMData(curXml, httpClient, hasNextLink));
               List<string> l = CRMModify.GetJObjectListValue(_jobj, "invoice_no");
               for (int i = 0; i < l.Count; i++)
               {
                   Console.WriteLine(i.ToString() + " -> " + l[i].ToString());
                   totalcount++;
               }

               if (_jobj.ContainsKey("@odata.nextLink"))
               {
                   pagingnumber++;
                   curXml = _jobj["@odata.nextLink"].ToString();
                   hasNextLink = true;
               }
               else
               {
                   break;
               }
           }
           Console.WriteLine("total pages : " + pagingnumber.ToString() + " total records: " + totalcount.ToString());
           System.Threading.Thread.Sleep(10000);
       }
   }
   catch (Exception ex)
   {
       throw ex;
   }
   finally
   {
       httpClient.Dispose();
   }
}