启动第二个Activity

activity_main.xml文件：

<?

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

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

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    >

   <Button

       android:id="@+id/myButton"

       android:layout_width="wrap_content"

       android:layout_height="wrap_content"

       android:text="启动第二个Activilty"

       />

</RelativeLayout>

创建activity_second.xml文件：

<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:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    android:paddingBottom="@dimen/activity_vertical_margin"

    tools:context="com.example.z1178.test.SecondActivity">

    <TextView

        android:id="@+id/secondView"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="第二个Activity"

        />

</RelativeLayout>

SecondActivity.java:

package com.example.z1178.test;

import android.os.Bundle;

import android.support.v7.app.ActionBarActivity;

public class SecondActivity extends ActionBarActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_second);

    }

}

MainActivity.java文件：

package com.example.z1178.test;

import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

public class MainActivity extends Activity {

    private static final String TAG="debug";

    private Button myButton;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

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

        buttonClickListener listener=new buttonClickListener();

        myButton.setOnClickListener(listener);

    }

    class  buttonClickListener implements View.OnClickListener{

        @Override

        public void onClick(View v) {

            Intent intent=new Intent();

            //setClass的第一个參数为Context对象（Activity为其子类），第二个參数为要启动的Activity

            intent.setClass(MainActivity.this,SecondActivity.class);

            startActivity(intent);

        }

    }

}

AndroidManifest.xml文件：

<?

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

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

    package="com.example.z1178.test" >

    <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=".SecondActivity"

            android:label="@string/title_activity_second" >

        </activity>

    </application>

</manifest>

对于back stack。其维护的Activity对象，我们须要注意的是，其总是显示顶端的Activity，当我们按回退键的时候，back stack会依照与进去栈的相反顺序依次显示相应的Activity。