知识点

• 俩种退出程序的方法
• 复制集合
• 同步的用法
• 字符数组
• 工厂模式，生产fatgment，解决了碎片重复创建的问题
• 全局上下文
• actionbar用法
• fargmentadapter，当viewpager里是fargment的话更方便

1.抽取BaseActivity   管理所有activity 方便退出

1. public class BaseActivity extends ActionBarActivity {	// 管理运行的所有的activity	public final static List
            
              mActivities = new LinkedList
             
              ();//增删快	//使用广播也可以，如果当前Activity想退出可以，sendReceiver//	private KillAllReceiver receiver;//	private class KillAllReceiver extends BroadcastReceiver{////		@Override//		public void onReceive(Context context, Intent intent) {//			finish();//		}//	}				@Override 	protected void onCreate(Bundle savedInstanceState) {		super.onCreate(savedInstanceState);//		receiver=new KillAllReceiver();//		IntentFilter filter=new IntentFilter("com.itheima.google.killall");//		registerReceiver(receiver, filter);				//解决同步问题，不可以添加的时候删除		synchronized (mActivities) {			mActivities.add(this);		}		init();//定义几个方法子类去实现，代码不臃肿，这个是初始化view前的操作		initView();		initActionBar();	}	@Override	protected void onDestroy() {		super.onDestroy();		synchronized (mActivities) {			mActivities.remove(this);		}//		if(receiver!=null){//			unregisterReceiver(receiver);//			receiver=null;//		}	}	public void killAll() {		// 复制了一份mActivities 集合，因为不能在操作mActivities 的时候去遍历，就是这样复制的		List
              
                copy;		synchronized (mActivities) {			copy = new LinkedList
               
                (mActivities);		}		for (BaseActivity activity : copy) {			activity.finish();		}		// 杀死当前的进程		android.os.Process.killProcess(android.os.Process.myPid());	}	protected void initActionBar() {	}	protected void initView() {	}	protected void init() {	}}
               
              
             
            

2.MainActivity 

public class MainActivity extends BaseActivity implements		OnQueryTextListener {	private DrawerLayout mDrawerLayout;	private ActionBarDrawerToggle drawerToggle;	private ViewPager mViewPager;	private PagerTabStrip pager_tab_strip;	private String[] tab_names;  // 标签的名字	@Override	protected void initActionBar() {		ActionBar actionBar = getSupportActionBar();		actionBar.setDisplayHomeAsUpEnabled(true);		actionBar.setHomeButtonEnabled(true);		drawerToggle = new ActionBarDrawerToggle(this,				mDrawerLayout, R.drawable.ic_drawer_am, R.string.open_drawer,				R.string.close_drawer){					@Override					public void onDrawerClosed(View drawerView) {						super.onDrawerClosed(drawerView);						Toast.makeText(getApplicationContext(), "抽屉关闭了", 0).show();					}					@Override					public void onDrawerOpened(View drawerView) {						super.onDrawerOpened(drawerView);						Toast.makeText(getApplicationContext(), "抽屉打开了", 0).show();					}					};		mDrawerLayout.setDrawerListener(drawerToggle);		//  让开关和actionbar建立关系 		drawerToggle.syncState();			}	@Override	protected void init() {		tab_names = UiUtils.getStringArray(R.array.tab_names);	}		@Override	protected void initView() {		setContentView(R.layout.activity_main);		mDrawerLayout = (DrawerLayout) findViewById(R.id.dl);		mViewPager=(ViewPager) findViewById(R.id.vp);		pager_tab_strip=(PagerTabStrip) findViewById(R.id.pager_tab_strip);		//  设置标签下划线的颜色		pager_tab_strip.setTabIndicatorColor(getResources().getColor(R.color.indicatorcolor));				mViewPager.setAdapter(new MainAdpater(getSupportFragmentManager()));		//sendBroadcast(new Intent("com.itheima.google.killall"));		//Log.i(tag, msg)	}	private class MainAdpater extends FragmentStatePagerAdapter{		public MainAdpater(FragmentManager fm) {			super(fm);		}		// 每个条目返回的fragment		//  0		@Override		public Fragment getItem(int position) {			//  通过Fragment工厂  生产Fragment   			return FragmentFactory.createFragment(position);		}		// 一共有几个条目 		@Override		public int getCount() {			return tab_names.length;		}		// 返回每个条目的标题		@Override		public CharSequence getPageTitle(int position) {			return tab_names[position];		}			}	@SuppressLint("NewApi")	@Override	public boolean onCreateOptionsMenu(Menu menu) {		getMenuInflater().inflate(R.menu.activity_main, menu);		// 如果运行的环境 (部署到什么版本的手机 )大于3.0		if (android.os.Build.VERSION.SDK_INT > 11) {			SearchView searchView = (SearchView) menu.findItem(					R.id.action_search).getActionView();			searchView.setOnQueryTextListener(this);// 搜索的监听		} 		return true;	}		/** 处理actionBar菜单条目的点击事件 */	public boolean onOptionsItemSelected(MenuItem item) {		if (item.getItemId() == R.id.action_search) {			Toast.makeText(getApplicationContext(), "搜索", 0).show();		}		return drawerToggle.onOptionsItemSelected(item)|super.onOptionsItemSelected(item);	}	// 当搜索提交的时候	@Override	public boolean onQueryTextSubmit(String query) {		Toast.makeText(getApplicationContext(), query, 0).show();		return true;	}	// 当搜索的文本发生变化	@Override	public boolean onQueryTextChange(String newText) {		return true;	}}

　　

3.UiUtils 

1. public class UiUtils {	/**	 * 获取到字符数组 	 * @param tabNames  字符数组的id	 */	public static String[] getStringArray(int tabNames) {		return getResource().getStringArray(tabNames);	}	public static Resources getResource() {		return BaseApplication.getApplication().getResources();	}		/** dip转换px */	public static int dip2px(int dip) {		final float scale = getResource().getDisplayMetrics().density;		return (int) (dip * scale + 0.5f);	}	/** pxz转换dip */	public static int px2dip(int px) {		final float scale = getResource().getDisplayMetrics().density;		return (int) (px / scale + 0.5f);	}}

    

这样定义数组：string.xml里

1. <string-array name="tab_names">
2. <item>首页</item>
3. <item>应用</item>
4. <item>游戏</item>
5. <item>专题</item>
6. <item>分类</item>
7. <item>排行</item>
8. </string-array>

4.

FragmentFactory

1. public class FragmentFactory {	private static Map
              
                mFragments = new HashMap
               
                ();	public static Fragment createFragment(int position) {		Fragment fragment = null;		fragment = mFragments.get(position);  //在集合中取出来Fragment		if (fragment == null) {  //如果再集合中没有取出来 需要重新创建			if (position == 0) {				fragment = new HomeFragment();			} else if (position == 1) {				fragment = new AppFragment();			} else if (position == 2) {				fragment = new GameFragment();			} else if (position == 3) {				fragment = new SubjectFragment();			} else if (position == 4) {				fragment = new CategoryFragment();			} else if (position == 5) {				fragment = new TopFragment();			}			if (fragment != null) {				mFragments.put(position, fragment);// 把创建好的Fragment存放到集合中缓存起来			}		}		return fragment;	}}
               
              

   　　

通过这样获取上下文

/** * 代表当前应用程序 * @author itcast * */public class BaseApplication extends Application {	private static BaseApplication application;	@Override	public void onCreate() {		super.onCreate();		application=this;			}	public static Context getApplication() {		return application;	}}