安卓：ActionBar的样式（这里介绍3种）

<span style="font-size:18px;"><LinearLayout 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:orientation="vertical">

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="点击按钮跳不同主题界面" />
<Button
android:id="@+id/bt1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="light主题"
android:onClick="click"/>
<Button
android:id="@+id/bt2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="holo主题"
android:onClick="click"/>
<Button
android:id="@+id/bt3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="NoActionBar主题"
android:onClick="click"/>

</LinearLayout>
</span>

<span style="font-size:18px;">package com.example.day19_actionbartheme;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}

public void click(View v)
{
switch(v.getId())
{
case R.id.bt1:
Intent intent=new Intent(MainActivity.this,LightTheme.class);
startActivity(intent);
break;
case R.id.bt2:
Intent intent2=new Intent(MainActivity.this,HoloTheme.class);
startActivity(intent2);
break;
case R.id.bt3:
Intent intent3=new Intent(MainActivity.this,NoActionBarTheme.class);
startActivity(intent3);
break;
}
}

}
</span>

<span style="font-size:18px;">package com.example.day19_actionbartheme;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

public class HoloTheme extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_theme);
}

@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;
}

}
</span>

<span style="font-size:18px;"><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=".LightTheme" >

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/hello_world" />

</RelativeLayout>
</span>

<span style="font-size:18px;">        <activity
android:name="com.example.day19_actionbartheme.LightTheme"
android:label="@string/title_activity_light_theme" >
</activity>
<activity
android:name="com.example.day19_actionbartheme.HoloTheme"
android:theme="@android:style/Theme.Holo">
</activity>
<activity
android:name="com.example.day19_actionbartheme.NoActionBarTheme"
android:theme="@android:style/Theme.NoTitleBar">
</activity></span>