Android ActionBar 初探

1.指南，例子，个人感觉

首先上官网指南链接http://developer.android.com/guide/topics/ui/actionbar.html

参考了官网上的例子http://developer.android.com/samples/ActionBarCompat-Basic/index.html

初看指南感觉ActionBar 的作用类似于web 开发中常用的include heder.html ,如cnblog 页面总第一行 。

2.兼容问题： sdk 11及11以上 可以直接使用，sdk 11以下则需要support-v7

PS:使用这两种在配置文件里也要区别如下 ,注意下面#后面是使用sdk 11自带的ActionBar 配置

<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:support="http://schemas.android.com/apk/res-auto"
# xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context="com.example.actionbar.MainActivity" >

    <item
        android:id="@+id/action_settings"
        android:orderInCategory="100"
        android:title="@string/action_settings"
        support:showAsAction="never"
        #app:showAsAction="never"/>

    <item
        android:id="@+id/menu_refresh"
        android:icon="@drawable/ic_action_refresh"
        android:title="@string/menu_refresh"
        support:showAsAction="ifRoom"
        />
        

3.构造方法

有配置文件，和程序代码里构建两种

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
　　　  　配置文件构建
        getMenuInflater().inflate(R.menu.main, menu);
        MenuItem locationItem = menu.add(0,R.id.menu_location,0,R.string.menu_location);

        程序构建
        locationItem.setIcon(R.drawable.ic_action_location);
        MenuItemCompat.setShowAsAction(locationItem, MenuItem.SHOW_AS_ACTION_IF_ROOM);
        return true;
    }

4.全代码

package com.example.actionbar;

import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.view.MenuItemCompat;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;

//@SuppressLint("NewApi")
public class MainActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.sample_main);
   // android.app.ActionBar actionBar =  getActionBar();
    //actionBar.hide();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        getMenuInflater().inflate(R.menu.main, menu);
        MenuItem locationItem = menu.add(0,R.id.menu_location,0,R.string.menu_location);
        locationItem.setIcon(R.drawable.ic_action_location);
        MenuItemCompat.setShowAsAction(locationItem, MenuItem.SHOW_AS_ACTION_IF_ROOM);
        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.

        switch (item.getItemId()) {
        case R.id.menu_refresh:
            // Here we might start a background refresh task
            return true;

        case R.id.menu_location:
            // Here we might call LocationManager.requestLocationUpdates()
            return true;

        case R.id.menu_settings:
            // Here we would open up our settings activity
            return true;
        case R.id.action_settings:
            // Here we would open up our settings activity
            return true;
    }

        return super.onOptionsItemSelected(item);
    }
}

5.后续.....