onClick von 2ter activity

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;import android.view.View; 
 public class MainActivity extends Activity { 
 
@Overrideprotected void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState);setContentView(R.layout.activity_main); 
}
 
@Overridepublic 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; 
}
 public void testklick (View view){setContentView(R.layout.activity_over); 
}
 
}

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
 
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/hello_world" />
 
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/textView1"
android:layout_below="@+id/textView1"
android:layout_marginLeft="30dp"
android:layout_marginTop="132dp"
android:onClick="testklick"
android:text="Button" />
 </RelativeLayout>

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;import android.support.v4.app.NavUtils; 
 public class OverActivity extends Activity { 
 
@Overrideprotected void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState);setContentView(R.layout.activity_over); 
// Show the Up button in the action bar.
setupActionBar();
}
 /** 
* Set up the {@link android.app.ActionBar}.
*/private void setupActionBar() { 
 getActionBar().setDisplayHomeAsUpEnabled(true); 
 
}
 
@Overridepublic boolean onCreateOptionsMenu(Menu menu) { 
// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.over, menu);return true; 
}
 
@Overridepublic boolean onOptionsItemSelected(MenuItem item) { 
switch (item.getItemId()) {case android.R.id.home: 
// This ID represents the Home or Up button. In the case of this
// activity, the Up button is shown. Use NavUtils to allow users
// to navigate up one level in the application structure. For
// more details, see the Navigation pattern on Android Design:
//
// http://developer.android.com/design/patterns/navigation.html#up-vs-back
//NavUtils.navigateUpFromSameTask(this);return true; 
}return super.onOptionsItemSelected(item); 
}
 public void test2klick(View view){setContentView(R.layout.activity_main); 
}
}

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".OverActivity" >
 
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/hello_world" />
 
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/textView1"
android:layout_below="@+id/textView1"
android:layout_marginLeft="46dp"
android:layout_marginTop="74dp"
android:onClick="test2klick"
android:text="Button" />
 </RelativeLayout>