Follow Below Steps.
1. Create New Android Project. Name It Exit as i did.
2. Now Open Your activity_main.xml. Follow Path .res --> Layout --> activity_main.xml.
I Have Added Analog Clock To Graphical Layout Because I don't Wanted To left screen as blank so..
You May Left Your Screen Blank For Now.
3. Type Below Code To Your activity_main.xml
activity_main.xml
<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" >
<AnalogClock
android:id="@+id/analogClock1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="64dp"
android:layout_marginTop="37dp" />
</RelativeLayout>
4. Open Your MainActivity.java File And Type Below code.
MainActivity.java
package arshad.exit;
import android.os.Bundle;
import
android.app.Activity;
import
android.app.AlertDialog;
import
android.content.DialogInterface;
import android.view.Menu;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle
savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void onBackPressed() {
new AlertDialog.Builder(this)
.setMessage("Do you want
to exit?")
.setCancelable(false)
.setPositiveButton("Yes", new
DialogInterface.OnClickListener() {
public void
onClick(DialogInterface dialog, int id) {
MainActivity.this.finish();
}
})
.setNegativeButton("No", null)
.show();
}
@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;
}
}
5. Now Compile And Run Your Project As Android Application.
6. When Your Application Executes Press Back Button. The Alert Box Will Ask To Exit.
My Output Screen's Are As Below.
