泛微OA的第三方异构系统调用流程，请提供c#的演示代码

泛微OA的第三方异构系统调用流程通常包括以下步骤：

1. 获取Token：首先需要获取Token，通过以下API接口获取Token

http://服务器地址:端口号/weaver/batch/authentication.do

请求方式：POST

请求参数：

{
    "params": {
        "language": "7",
        "loginid": "账号",
        "password": "密码",
        "useragent": "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.146 Safari/537.36",
        "domain": "泛微OA的域名"
    },
    "requestid": "1",
    "serviceid": "rest",
    "ticket": "null"
}

2. 调用API：获取Token后，就可以调用API接口了。通过以下API接口调用。

http://服务器地址:端口号/rest/workflow/request/create.action

请求方式：POST

请求参数：

{
    "requestname": "测试流程",
    "workflowid": "流程编号",
    "operatorid": "操作人编号",
    "csrftoken": "token",
    "formdata": [{
        "fieldid": "字段ID",
        "fieldvalue": "字段值"
    }, {
        "fieldid": "字段ID",
        "fieldvalue": "字段值"
    }],
    "attachments": [{
        "filename": "文件名",
        "filebody": "文件内容",
        "filesize": "文件大小"
    }]
}

其中，需要替换的参数有：

- 服务器地址：泛微OA服务器地址
- 端口号：泛微OA端口号
- 账号：泛微OA登录账号
- 密码：泛微OA登录密码
- 泛微OA的域名：泛微OA的域名
- 流程编号：泛微OA中指定的流程编号
- 操作人编号：泛微OA中指定的操作人编号
- token：获取到的Token
- 字段ID：泛微OA中定义的字段ID
- 字段值：需要提交的字段值
- 文件名：需要提交的文件名
- 文件内容：需要提交的文件内容
- 文件大小：需要提交的文件大小

演示代码如下：

using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Text;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            // 获取Token
            string token = GetToken("账号", "密码", "泛微OA的域名");

            // 调用API
            string result = CallAPI(token, "流程编号", "操作人编号", "字段ID", "字段值");

            Console.WriteLine(result);
        }

        // 获取Token
        static string GetToken(string loginid, string password, string domain)
        {
            string url = "http://服务器地址:端口号/weaver/batch/authentication.do";

            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            request.Method = "POST";
            request.ContentType = "application/json;charset=UTF-8";

            string postData = "{\"params\":{\"language\":\"7\",\"loginid\":\"" + loginid + "\",\"password\":\"" + password + "\",\"useragent\":\"Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.146 Safari/537.36\",\"domain\":\"" + domain + "\"},\"requestid\":\"1\",\"serviceid\":\"rest\",\"ticket\":\"null\"}";

            byte[] bytes = Encoding.UTF8.GetBytes(postData);
            request.ContentLength = bytes.Length;

            Stream stream = request.GetRequestStream();
            stream.Write(bytes, 0, bytes.Length);
            stream.Close();

            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            Stream responseStream = response.GetResponseStream();
            StreamReader reader = new StreamReader(responseStream, Encoding.UTF8);

            string result = reader.ReadToEnd();

            reader.Close();
            responseStream.Close();
            response.Close();

            int start = result.IndexOf("csrfToken\":\"") + 12;
            int end = result.IndexOf("\"", start);

            string token = result.Substring(start, end - start);

            return token;
        }

        // 调用API
        static string CallAPI(string token, string workflowid, string operatorid, string fieldid, string fieldvalue)
        {
            string url = "http://服务器地址:端口号/rest/workflow/request/create.action";

            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            request.Method = "POST";
            request.ContentType = "application/json;charset=UTF-8";
            request.Headers.Add("X-CSRF-TOKEN", token);

            string postData = "{\"requestname\":\"测试流程\",\"workflowid\":\"" + workflowid + "\",\"operatorid\":\"" + operatorid + "\",\"csrftoken\":\"" + token + "\",\"formdata\":[{\"fieldid\":\"" + fieldid + "\",\"fieldvalue\":\"" + fieldvalue + "\"}],\"attachments\":[]}";

            byte[] bytes = Encoding.UTF8.GetBytes(postData);
            request.ContentLength = bytes.Length;

            Stream stream = request.GetRequestStream();
            stream.Write(bytes, 0, bytes.Length);
            stream.Close();

            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            Stream responseStream = response.GetResponseStream();
            StreamReader reader = new StreamReader(responseStream, Encoding.UTF8);

            string result = reader.ReadToEnd();

            reader.Close();
            responseStream.Close();
            response.Close();

            return result;
        }
    }
}

注意：代码中的参数需要根据实际情况进行替换。