[WebService(Namespace = "http://tmpuri.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 WebServer : System.Web.Services.WebService
    {
        [WebMethod]
        public string CheckAndLogin(string userID, string userPwd)
        {
            string rtn = string.Empty;
            //登录简单验证
            BLL.UsersTable bll_Users = new BLL.UsersTable();
            using (StreamWriter sw = new StreamWriter("d:\\webservice_ch.txt", true))
            {
                sw.WriteLine("userID为：" + userID + "；       userPwd为：" + userPwd);
            }
            DataTable dt = bll_Users.GetList("UserLogin='" + userID + "' and UserPwd='" + userPwd + "'").Tables[0];
            if (dt.Rows.Count < 1)
            {
                rtn = "usernotfound";
            }
            else
            {
                rtn = dt.Rows[0]["UserName"].ToString();
            }
            return rtn;
        }
}

private void soapCheck(){
        String nameSpace = "http://tmpuri.org/";
        String methodName = "CheckAndLogin";
        //String url = "http://192.168.50.148/PDA/WebService/WebServer.asmx";
        String url = "http://192.168.1.9/PDA/WebService/WebServer.asmx";
        String soapAction = "http://tmpuri.org/CheckAndLogin";
        
        try{
            String userID = this.txtName.getText().toString();
            String userPwd = this.txtPwd.getText().toString();
            //request
            SoapObject request = new SoapObject(nameSpace, methodName);
            request.addProperty("userID", userID);
            request.addProperty("userPwd", userPwd);
            //envelope
            SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
            //envelope.encodingStyle = 
            envelope.dotNet=true;
            envelope.setOutputSoapObject(request);
            //call
            HttpTransportSE ht = new HttpTransportSE(url);
              ht.call(soapAction, envelope); 
              
              SoapObject result = (SoapObject) envelope.bodyIn;
              String txt = result.toString();          
              
              new AlertDialog.Builder(this).setMessage(result.getProperty("CheckAndLoginResult").toString()).create().show();
              
        }  catch(Exception ex){
            new AlertDialog.Builder(this).setMessage(ex.getMessage()).create().show();
        }
}