classlar arasında view transferi

merhaba arkadaşlar.. Ben bir activity içerisinde o activity için tanımlı layouttaki nesneleri 

tüm procedurlerde ve içerisine tanımlı classlarda kullanılabilmek istiyorum bunun için şöyle bir tanımlama yaptım ama sistem daha application açılırken çakılıyor

package com.example.derunservis;

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.os.Build;

import org.ksoap2.SoapEnvelope; 
import org.ksoap2.serialization.PropertyInfo; 
import org.ksoap2.serialization.SoapObject; 
import org.ksoap2.serialization.SoapSerializationEnvelope; 
import org.ksoap2.transport.HttpTransportSE; 

public class MainActivity extends ActionBarActivity {
    private String[] Liste;
    private static final String NAMESPACE = "http://tempuri.org/"; 
    private static final String URL = "http://duru/DeroidServer/DeroidService.asmx"; 
    private static final String METHOD_NAME = "GetMusteri"; 
    private static final String SOAP_ACTION = "http://duru/DeroidServer/DeroidService.asmx/GetNusteri"; // örnek: http://deneme/webservice.asmx/kullanılacak_method - See more at: http://blog.melihmucuk.com/android-programlama-dotnet-web-service-kullanimi/#sthash.yYEbAGCo.dpuf
    
    private EditText edtCariID=new EditText(this);
    private EditText edtCariKod=new EditText(this);
    private EditText edtUnvan=new EditText(this);
    private Button btnBul=new Button(this);
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {

        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);
            return rootView;
        }
    }

}