package com.fish.helloworld;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;public class Forwarding extends Activity {    private backButton_OnClickListener backButtonListener = new backButton_OnClickListener();        class backButton_OnClickListener implements OnClickListener{        public void onClick(View v){            Intent intent = new Intent();            intent.setClass(Forwarding.this, MainActivity.class);            startActivity(intent);            finish();        }    }         @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_forwarding);                final Button backButton = (Button)findViewById(R.id.button1);        backButton.setOnClickListener(backButtonListener);    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.forwarding, 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);    }}

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.fish.helloworld"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="17"        android:targetSdkVersion="17" />    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name=".MainActivity"            android:label="@string/app_name" >        </activity>        <activity            android:name=".Forwarding"            android:label="@string/title_activity_forwarding" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>