how to send multipart/form-data in web services?

Question

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.Script.Serialization;

using System.Web.Script.Services;

using System.Web.Services;

using Newtonsoft.Json;

using System.Net;

namespace WebServiceDemo.Api

{

/// <summary>

/// Summary description for Api

/// </summary>

[WebService(Namespace = "http://tempuri.org/")]

[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]

[System.ComponentModel.ToolboxItem(false)]

// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.

[System.Web.Script.Services.ScriptService]

public class Api : System.Web.Services.WebService

{

[System.Web.Services.WebMethod(EnableSession=true)]

[ScriptMethod(ResponseFormat = ResponseFormat.Json)]

public string Login(string glcode,string password)

{

var objList = new CommanListView<String>();

var lsi = new List<string>();

lsi.Add(glcode);

lsi.Add(password);

objList.Entiry = lsi;

return CommanAttribut.GetJsonSerlizer(objList);

}

}

}

error 

System.InvalidOperationException: Request format is invalid: multipart/form-data; boundary=----WebKitFormBoundary79Ky1A1Kfyyy7qUi.

at System.Web.Services.Protocols.HttpServerProtocol.ReadParameters()

at System.Web.Services.Protocols.WebServiceHandler.CoreProcessRequest()

that error have getting by postman.