Passing parameter from android web service to .net

I am using ksoap2 to call .net web services. The call works just fine, except when I pass parameters. Past parameters are always obtained as zero values ​​by the web service. I don’t know what the problem is, I hope someone can help. Thank,

My code is below, please help me

package com.android.countrycode;

import org.ksoap2.SoapEnvelope;
import org.ksoap2.serialization.PropertyInfo;
import org.ksoap2.serialization.SoapObject;
import org.ksoap2.serialization.SoapSerializationEnvelope;
import org.ksoap2.transport.HttpTransportSE;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;

public class CountryActivity extends Activity {
    /** Called when the activity is first created. */

    private static final String SOAP_ACTION = "http://www.webserviceX.NET/GetCountryByCountryCode";
    private static final String OPERATION_NAME = "GetCountryByCountryCode";
    private static final String WSDL_TARGET_NAMESPACE = "http://www.webserviceX.NET/";
    private static final String SOAP_ADDRESS = "http://www.webservicex.net/country.asmx";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        TextView textView = new TextView(this);
        setContentView(textView);
        SoapObject request = new SoapObject(WSDL_TARGET_NAMESPACE,OPERATION_NAME);
        //PropertyInfo pi = new PropertyInfo();
        //pi.setName("CountryCode");
        //pi.setValue("AS");
        //request.addProperty(pi);
        //request.addAttribute("CountryName", "Portugal");
        //request.setProperty(1, "Portugal");
        request.addProperty("CountryCode","AS");
        SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
        envelope.dotNet = true;
        envelope.setOutputSoapObject(request);
        HttpTransportSE httpTransport = new HttpTransportSE(SOAP_ADDRESS);
        try
        {

        httpTransport.call(SOAP_ACTION, envelope);
        Object response = envelope.getResponse();
        textView.setText(response.toString());
        System.out.println(response.toString());
        }
        catch (Exception exception)
        {
        String exceptionStr=exception.toString();
        textView.setText(exceptionStr);
        System.out.println(exceptionStr);
        Log.i("TAG",exceptionStr);
        }

    }
}