Using KSOAP in Android to access Webservice don't work

Question

Solved it with a Asynctask => AsyncCallWS, thnx Raghunandan.

Remember to download the Ksoap from here

and add it to the libs folder in Eclipse

Here is all my code:

import org.ksoap2.SoapEnvelope;
import org.ksoap2.serialization.PropertyInfo;
import org.ksoap2.serialization.SoapObject;
import org.ksoap2.serialization.SoapPrimitive;
import org.ksoap2.serialization.SoapSerializationEnvelope;
import org.ksoap2.transport.HttpTransportSE;
import android.os.AsyncTask;



public class MainActivity extends Activity {

    private final String NAMESPACE = "http://www.w3schools.com/webservices/";
    private final String URL = "http://www.w3schools.com/webservices/tempconvert.asmx";
    private final String SOAP_ACTION = "http://www.w3schools.com/webservices/CelsiusToFahrenheit";
    private final String METHOD_NAME = "CelsiusToFahrenheit";
    private String TAG = "PGGURU";
    private static String celcius;
    private static String fahren;
    Button b;
    TextView tv;
    EditText et;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //Celcius Edit Control
        et = (EditText) findViewById(R.id.editText1);
        //Fahrenheit Text control
        tv = (TextView) findViewById(R.id.tv_result);
        //Button to trigger web service invocation
        b = (Button) findViewById(R.id.button1);
        //Button Click Listener
        b.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                //Check if Celcius text control is not empty
                if (et.getText().length() != 0 && et.getText().toString() != "") {
                    //Get the text control value
                    celcius = et.getText().toString();
                    //Create instance for AsyncCallWS
                    AsyncCallWS task = new AsyncCallWS();
                    //Call execute 
                    task.execute();
                //If text control is empty
                } else {
                    tv.setText("Please enter Celcius");
                }
            }
        });
    }

    public void getFahrenheit(String celsius) {
        //Create request
        SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);
        //Property which holds input parameters
        PropertyInfo celsiusPI = new PropertyInfo();
        //Set Name
        celsiusPI.setName("Celsius");
        //Set Value
        celsiusPI.setValue(celsius);
        //Set dataType
        celsiusPI.setType(double.class);
        //Add the property to request object
        request.addProperty(celsiusPI);
        //Create envelope
        SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(
                SoapEnvelope.VER11);
        envelope.dotNet = true;
        //Set output SOAP object
        envelope.setOutputSoapObject(request);
        //Create HTTP call object
        HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);

        try {
            //Invole web service
            androidHttpTransport.call(SOAP_ACTION, envelope);
            //Get the response
            SoapPrimitive response = (SoapPrimitive) envelope.getResponse();
            //Assign it to fahren static variable
            fahren = response.toString();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private class AsyncCallWS extends AsyncTask<String, Void, Void> {
        @Override
        protected Void doInBackground(String... params) {
            Log.i(TAG, "doInBackground");
            getFahrenheit(celcius);
            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            Log.i(TAG, "onPostExecute");
            tv.setText(fahren + "° F");
        }

        @Override
        protected void onPreExecute() {
            Log.i(TAG, "onPreExecute");
            tv.setText("Calculating...");
        }

        @Override
        protected void onProgressUpdate(Void... values) {
            Log.i(TAG, "onProgressUpdate");
        }

    }   
}

I had to add permission in Manifest for internet, otherwise I got null as response.

<uses-permission android:name="android.permission.INTERNET" />

And this is my layout.xml file:

    <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:gravity="center"
        android:text="Celsius to Farenheit"
        android:textSize="30dp" />

    <EditText
        android:id="@+id/editText1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:numeric="integer"
        android:singleLine="true" />

    <Button
        android:id="@+id/button1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:gravity="center"
        android:text="Convert to Farenheit" />

    <TextView
        android:id="@+id/tv_result"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:text="" android:textSize="26dp"/>

</LinearLayout>

PS: If you have created your own WebService in Asp.Net and made it public, remember to change default namespace http://tempuri.org/ to something unique.

You change it in the WebService.asmx.cs

Like this:

[WebService(Namespace = "http://microsoft.com/webservices/")]