一直很想弄清楚好多应用中是如何实现换皮肤这项功能的，花了下午点时间，查了下资料也实现了个切换主题的Demo;
首先要感谢下这位大哥,参阅了下他写的文件http://www.eoeandroid.com/forum-viewthread-tid-31756-highlight-%E7%9A%AE%E8%82%A4.html
好了，废话不多说了，该切换主题的demo里面一共实现了两个功能，其一，搜索已经安装的皮肤，其二，应用安装的皮肤。
主项目包名为org.leepood.skindemo,主题项目的包名为org.leepood.skin.blue,org.leepood.skin.red,等等，只要前缀是org.leepood.skin.就行。
首先是查找已安装主题的代码:
package org.leepood.skindemo;import java.util.ArrayList;import java.util.List;import android.app.Activity;import android.app.ProgressDialog;import android.content.Context;import android.content.Intent;import android.content.SharedPreferences;import android.content.pm.PackageInfo;import android.content.pm.PackageManager;import android.content.pm.PackageManager.NameNotFoundException;import android.content.res.Resources;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.view.ContextMenu;import android.view.LayoutInflater;import android.view.MenuItem;import android.view.View;import android.view.ViewGroup;import android.view.ContextMenu.ContextMenuInfo;import android.view.View.OnCreateContextMenuListener;import android.widget.BaseAdapter;import android.widget.ImageView;import android.widget.ListView;import android.widget.TextView;import android.widget.Toast;import android.widget.AdapterView.AdapterContextMenuInfo;public class Main extends Activity implements SharedPreferences.OnSharedPreferenceChangeListener{ private ListView listview; private Context c; private Handler mHandler; private ProgressDialog pDialog; private SkinAdapter adapter; private SharedPreferences sp; static final int MESSAGE_SEARCHED_SKIN=0; static final int MESSAGE_SEARCHING_SKIN=MESSAGE_SEARCHED_SKIN+1; static final int MESSAGE_SEARCHED_SKIN_FOR_NONTHING=MESSAGE_SEARCHING_SKIN+1; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); init(); pDialog.show(); new Thread(serachSkin).start(); } private void init() { c=this; mHandler=new Handler(){ @Override public void handleMessage(Message msg) { switch(msg.what) { case MESSAGE_SEARCHED_SKIN: ArrayList skins=(ArrayList) msg.obj;//获取skins adapter=new SkinAdapter(c, skins); listview.setAdapter(adapter); Toast.makeText(c, "查找到已经安装的皮肤", 1).show(); pDialog.dismiss(); break; case MESSAGE_SEARCHED_SKIN_FOR_NONTHING: Toast.makeText(c, "未查找到任何皮肤", 1).show(); pDialog.dismiss(); } } }; sp=this.getSharedPreferences("config",Context.MODE_WORLD_WRITEABLE); sp.registerOnSharedPreferenceChangeListener(this); listview=(ListView) findViewById(R.id.list); listview.setItemsCanFocus(false); listview.setChoiceMode(ListView.CHOICE_MODE_SINGLE); pDialog=new ProgressDialog(this); pDialog.setMessage("正在查找已经安装的皮肤"); listview.setOnCreateContextMenuListener(new OnCreateContextMenuListener() { public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { menu.add("使用该主题"); } }); } private Runnable serachSkin =new Runnable(){ public void run() { PackageManager manager=c.getPackageManager(); List packages=manager.getInstalledPackages(PackageManager.PERMISSION_GRANTED); ArrayList skins=new ArrayList(); for(PackageInfo info:packages) { //System.out.println(info.packageName); if(info.packageName.startsWith("org.leepood.skin.")) { skins.add(info); } } if(skins.size()>0) { Message msg=mHandler.obtainMessage(); msg.obj=skins; msg.what=MESSAGE_SEARCHED_SKIN; mHandler.sendMessage(msg); } else { mHandler.sendEmptyMessage(MESSAGE_SEARCHED_SKIN_FOR_NONTHING); } } }; private class SkinAdapter extends BaseAdapter { LayoutInflater mInflater; ArrayList datas; PackageManager manager; public SkinAdapter(Context c,ArrayList datas) { this.datas=datas; mInflater=LayoutInflater.from(c); manager=c.getPackageManager(); } public int getCount() { return datas.size(); } public Object getItem(int position) { return datas.get(position); } public long getItemId(int position) { return 0; } public View getView(int position, View convertView, ViewGroup parent) { if(convertView==null) { convertView=mInflater.inflate(R.layout.skin_item, null); } ImageView icon=(ImageView) convertView.findViewById(R.id.skin_icon); TextView skin_name=(TextView) convertView.findViewById(R.id.skin_name); PackageInfo info=datas.get(position); icon.setImageDrawable(info.applicationInfo.loadIcon(manager)); skin_name.setText(info.applicationInfo.loadLabel(manager)); return convertView; } } public void onThemeChanged(String newThemePackageName) { try { Context themeContext=this.createPackageContext(newThemePackageName, CONTEXT_IGNORE_SECURITY); Resources res=themeContext.getResources(); setControlsStyle(res); } catch (NameNotFoundException e) { e.printStackTrace(); } } private void setControlsStyle(Resources res) { listview.setBackgroundColor(res.getColor(R.color.ListView_bg)); } @Override public boolean onContextItemSelected(MenuItem item) { AdapterContextMenuInfo menuInfo=(AdapterContextMenuInfo)item.getMenuInfo(); PackageInfo info=(PackageInfo) adapter.getItem(menuInfo.position); sp.edit().putString("themePackage", info.packageName).commit(); return super.onContextItemSelected(item); } public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) { System.out.println("themeChange"); onThemeChanged(sharedPreferences.getString(key, "")); }}这段代码的含义就是去查找系统中安装的包名，若以org.leepood.skin.开头则说明该包为主题包,将其加入listview中显示出来。代码中使用了多线程避免时间过长堵塞UI。程序将当前主题配置保存在SharedPreference中,为SharedPreference注册了一个监听函数，当其值发生改变时自动调用新的样式。当然，这只是个demo而已,一开始加载Activity没有去读取主题，这个可以由大家自己去实现。
最后贴张图片:
Android实现主题切换机制2
昨天花了点时间实现了主题的切换，但是里面还是不够灵活，回去想了想可以用继承和回调函数来进一步灵活更改主题，现在记录下我的实现办法
首先一个自定义类ThemeActivity继承自Activity，这个类是以后所有Activity的父类，在这个类里面定义了一个接口
public interface OnThemeChangedListener
{
public void onChanged(String newThemePackageName);
}
接下来，首先是要给ThemeActivity注册一个主题切换的listener,代码如下:
public void setOnThemeChangedListener(OnThemeChangedListener listener)
{
this.listener=listener;
}
然后就是注册一个SharedPreference来监听xml的变化，当发生改变的时候自动去调用listener.onChanged方法，将新的主题包名传递过去，代码如下:
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,
String key) {
if(key.equals("themePackage"))
{
listener.onChanged(sp.getString("themePackage", ""));
}
}
接着在继承于ThemeActivity的子类里面首先是setOnThemeChangedListener.接着用一个匿名内部类搞定。好啦，代码可以见附件啦
1 楼 逍遥天下 2012-02-16
哈哈··谢谢群主啊
2 楼 xiangdream 2012-03-14
good