Java - Error conctar web service con android studio

-- Clase MainActivity

package com.example.andres.login;

import android.content.Intent;

import android.support.v7.app.ActionBarActivity;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.TextView;

import android.widget.Toast;

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;

public class MainActivity extends ActionBarActivity {

    private final String NAMESPACE = "http://schemas.xmlsoap.org/soap/encoding/";

    private final String URL = "http://10.0.0.56/ws_separador_bodega/ws_separador_bodega.php?wsdl";

    private final String SOAP_ACTION = "http://10.0.0.56/DUSOFT_FFMM_HOMIC/ws_separador_bodega/ws_separador_bodega.php/login";

    private final String METHOD_NAME = "login";

    private static String fahren;

    EditText et_nombre, et_apellido, et_resultado;

    Button btnAceptar;

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        btnAceptar = (Button) findViewById(R.id.btnAceptar);

        btnAceptar.setOnClickListener(new View.OnClickListener() {

            public void onClick(View arg0) {

                new HiloTask().execute();

                MainActivity mAuth = new MainActivity();

                loginAction();

            }

        });

    }

    public void loginAction() {

        SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);

        //et_resultado = (EditText) findViewById(R.id.et_resultado);

        //String resultado = et_resultado.getText().toString();

        et_nombre = (EditText) findViewById(R.id.et_nombre);

        String nombre = et_nombre.getText().toString();

        et_apellido = (EditText) findViewById(R.id.et_apellido);

        String apellido = et_apellido.getText().toString();

        PropertyInfo unameProp = new PropertyInfo();

        unameProp.setName("et_nombre");

        unameProp.setValue(nombre);

        unameProp.setType(String.class);

        request.addProperty(unameProp);

        PropertyInfo passwordProp = new PropertyInfo();

        passwordProp.setName("et_apellido");

        passwordProp.setValue(apellido);

        passwordProp.setType(String.class);

        request.addProperty(passwordProp);

        SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);

        envelope.setOutputSoapObject(request);

                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();

        }

    }

}

--Clase HiloTask

package com.example.andres.login;

import android.app.ProgressDialog;

import android.graphics.Color;

import android.os.AsyncTask;

import android.text.SpannableString;

import android.text.style.ForegroundColorSpan;

import android.text.style.RelativeSizeSpan;

import android.util.Log;

/**

 * Created by Andres on 23/07/2015.

 */

class HiloTask extends AsyncTask<String, Void, String> {

    ProgressDialog pDialog;

    @Override

    protected void onPreExecute() {

        super.onPreExecute();

        Log.d("Hola", "Descargando");

        pDialog = new ProgressDialog(MainActivity.this); " AQUI ME SALE ERROR EN LA PARTE MainActivity.this, dice: COM.EXAMPLE.ANDRES.LOGIN.MAINACTIVITY IS NOT AN ENCLOSING CLASS"

        pDialog.setMessage("Cargando base...");

        String message= "Ejecutando el proceso";

        SpannableString ss2 =  new SpannableString(message);

        ss2.setSpan(new RelativeSizeSpan(2f), 0, ss2.length(), 0);

        ss2.setSpan(new ForegroundColorSpan(Color.BLACK), 0, ss2.length(), 0);

        pDialog.setMessage(ss2);

        pDialog.setCancelable(false);

        pDialog.show();

    }

    @Override

    protected String doInBackground(String... params) {

        MainActivity mAuth = new MainActivity();

        mAuth.loginAction();

        return null;

    }

    @Override

    protected void onPostExecute(String result) {

        super.onPostExecute(result);

        Log.d("Holas", "descargando.");

        pDialog.dismiss();

    }

}

-- Android Manifest

--<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.example.andres.login" >

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

    <application

        android:allowBackup="true"

        android:icon="@mipmap/ic_launcher"

        android:label="@string/app_name"

        android:theme="@style/AppTheme" >

        <activity

            android:name=".MainActivity"

            android:label="@string/app_name" >

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

        <activity android:name=".Gracias"></activity>

    </application>

</manifest>

-- vista

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:orientation="vertical"

    tools:context=".MainActivity">

    <TextView

        android:layout_width="289dp"

        android:layout_height="wrap_content"

        android:textAppearance="?android:attr/textAppearanceLarge"

        android:text="Nombre:"

        android:id="@+id/textView"

        android:layout_alignParentBottom="true"

        android:layout_alignParentRight="true"

        android:layout_alignParentEnd="true"

        android:layout_marginRight="230dp" />

    <EditText

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:inputType="textPersonName"

        android:ems="10"

        android:id="@+id/et_nombre"

        android:hint="Nombre" />

    <TextView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:textAppearance="?android:attr/textAppearanceLarge"

        android:text="Apellido:"

        android:id="@+id/textView2" />

    <EditText

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:inputType="textPersonName"

        android:ems="10"

        android:id="@+id/et_apellido"

        android:hint="Apellido" />

    <Button

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="Aceptar"

        android:id="@+id/btnAceptar"

        android:onClick="onClickAceptar" />

</LinearLayout>