Android杂谈--获取系统程序和应用程序

做其他开发时的一个小例子，主要的功能

• 自定义Button(TextView来做Button)
• 通过点击不同的Button显示系统程序和应用程序
• 更改ListView选中时的背景色

PackageManager的功能：

　　•安装，卸载应用
　　•查询permission相关信息
　　•查询Application相关信息(application，activity，receiver，service，provider及相应属性等）
　　•查询已安装应用
　　•增加，删除permission
　　•清除用户数据、缓存，代码段等

先看看效果图，风格可以自己调整

代码就暂时不特别规范的写了，只是测试程序

main.xml，整体布局，默认TextView是没有事件监听的，需要设置其android:clickable属性为true

xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="" android:layout_width="fill_parent" android:layout_height="fill_parent" android:background="@drawable/background_color" android:orientation="vertical" > <LinearLayout android:layout_width="fill_parent" android:layout_height="10dip" /> <LinearLayout android:layout_width="fill_parent" android:layout_height="40dip" > <TextView android:id="@+id/button01" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_weight="1" android:text="普通应用" android:gravity="center" android:background="@drawable/button_selector" android:focusable="true" android:clickable="true" android:layout_marginLeft="10dip" /> <View android:layout_width="5px" android:layout_height="fill_parent" android:background="#FFFFFFFF"/> <TextView android:id="@+id/button02" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_weight="1" android:text="系统应用" android:gravity="center" android:background="@drawable/button_selector" android:focusable="true" android:clickable="true" android:layout_marginRight="10dip" /> LinearLayout> <ListView android:id="@+id/lv" android:layout_width="fill_parent" android:layout_height="wrap_content" android:fastScrollEnabled="true"> ListView>" LinearLayout>

ListView的item布局:listitem.xml，这里ImageView的大小最好设置为固定的，如果是wrap_content的话，不同应用程序的图标不一样大，显示出来很难看

xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@drawable/list_item_color_bg" android:orientation="horizontal" > <ImageView android:id="@+id/appicon" android:layout_width="48dip" android:layout_height="48dip" android:padding="5dp" /> <LinearLayout android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="wrap_content" > <TextView android:id="@+id/appName" android:layout_width="fill_parent" android:layout_height="wrap_content" /> <TextView android:id="@+id/packageName" android:layout_width="fill_parent" android:layout_height="wrap_content" /> LinearLayout> LinearLayout>

下面的是drawable下的一些文件

background_color.xml

xml version="1.0" encoding="utf-8"?> <shape xmlns:android="" > <gradient android:startColor="#FFFFFFFF" android:endColor="#FFFFFFFF" android:angle="270.0" android:centerY="0.3" android:centerColor="#FFBDBDBD" /> shape>

button_color.xml

xml version="1.0" encoding="utf-8"?> <shape xmlns:android="" > <gradient android:startColor="#FF7F7F7F" android:endColor="#FF000000" android:angle="270.0" /> shape>

button_selector.xml，这是点击TextView自定义的Button的selector文件

xml version="1.0" encoding="utf-8"?> <selector xmlns:android="" android:constantSize="true" > <item android:state_focused="true" > <shape> <gradient android:startColor="#FFE5CF33" android:endColor="#FFF1E7A2" android:angle="90.0" /> shape> item> <item android:state_enabled="true" android:state_pressed="false" > <shape> <gradient android:startColor="#FF1B1B1B" android:endColor="#FF969696" android:angle="90.0" /> shape> item> <item android:state_enabled="true" android:state_pressed="true"> <shape> <gradient android:startColor="#FF000000" android:endColor="#FF474747" android:angle="90.0" /> shape> item> <item android:state_enabled="false" android:state_pressed="true"> <shape> <gradient android:startColor="#FF000000" android:endColor="#ff474747" android:angle="90.0" /> shape> item> <item> <shape> <gradient android:startColor="#FF000000" android:endColor="#FF474747" android:angle="90.0" /> shape> item> selector>

list_item_color_bg.xml，这是点击ListView时item自定义的选中背景

xml version="1.0" encoding="utf-8"?> <selector xmlns:android="" > <item android:state_pressed="true" android:drawable="@color/green" >item> <item android:drawable="@color/white" >item> selector>

最后是源代码了

这里有几点注意

• 点击不同按钮后需要切换不同的视图，此时由于数据源已经改变，所以需要点击后立即变成改变后的结果，所以需要刷新ListView，使用adapter.notifyDataSetChanged()方法即可刷新ListView
• 系统应用程序和普通应用程序我放到了不同的ArrayList中了，如果感觉这部分设计有问题的话，希望高手指点

package com.loulijun.appshow; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import android.app.Activity; import android.content.Context; import android.content.pm.ApplicationInfo; import android.content.pm.PackageInfo; import android.content.pm.PackageManager; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.ImageView; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; public class AppShowActivity extends Activity { /** Called when the activity is first created. */ private TextView customAppsBtn, systemAppsBtn; private ListView lv; private List customApps; // 普通应用程序 private List systemApps; // 系统应用程序 MyAdapter adapter; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); customAppsBtn = (TextView)findViewById(R.id.button01); systemAppsBtn = (TextView)findViewById(R.id.button02); lv = (ListView)findViewById(R.id.lv); //加载系统应用和普通应用程序 loadApps(); adapter = new MyAdapter(this, customApps); lv.setAdapter(adapter); customAppsBtn.setOnClickListener(new TextView.OnClickListener() { @Override public void onClick(View v) { Toast.makeText(getApplicationContext(), "普通应用", Toast.LENGTH_SHORT).show(); //切换到普通程序列表 updateAppList(customApps); } }); systemAppsBtn.setOnClickListener(new TextView.OnClickListener() { @Override public void onClick(View v) { Toast.makeText(getApplicationContext(), "系统应用", Toast.LENGTH_SHORT).show(); //切换到系统程序列表 updateAppList(systemApps); } }); } //列出普通应用程序 private void loadApps() { customApps = new ArrayList(); systemApps = new ArrayList(); //得到PackageManager对象 PackageManager pm = this.getPackageManager(); //得到系统安装的所有程序包的PackageInfo对象 List packages = pm.getInstalledPackages(0); for(PackageInfo pi:packages) { //列出普通应用 if((pi.applicationInfo.flags&ApplicationInfo.FLAG_SYSTEM)<=0) { customApps.add(pi); } //列出系统应用，总是感觉这里设计的有问题，希望高手指点 if((pi.applicationInfo.flags&ApplicationInfo.FLAG_SYSTEM)>0) { systemApps.add(pi); } } } private void updateAppList(List apps) { adapter.setData(apps); adapter.notifyDataSetChanged(); } //ViewHolder静态类 static class ViewHolder { public ImageView appicon; public TextView appName; public TextView packageName; } class MyAdapter extends BaseAdapter { private LayoutInflater mInflater = null; private List apps; private MyAdapter(Context context, List apps) { this.mInflater = LayoutInflater.from(context); this.apps = apps; } //setData()要在MyAdapter类里设置，用于设置数据源 public void setData(List apps) { this.apps = apps; } @Override public int getCount() { // TODO Auto-generated method stub return customApps.size(); } @Override public Object getItem(int position) { // TODO Auto-generated method stub return position; } @Override public long getItemId(int position) { // TODO Auto-generated method stub return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { ViewHolder holder = null; if(convertView == null) { holder = new ViewHolder(); convertView = mInflater.inflate(R.layout.list_item, null); holder.appicon = (ImageView)convertView.findViewById(R.id.appicon); holder.appName = (TextView)convertView.findViewById(R.id.appName); holder.packageName = (TextView)convertView.findViewById(R.id.packageName); convertView.setTag(holder); }else { holder = (ViewHolder)convertView.getTag(); } PackageManager pm = getPackageManager(); // 得到pm对象 PackageInfo info = apps.get(position); ApplicationInfo appInfo = info.applicationInfo; holder.appicon.setImageDrawable(pm.getApplicationIcon(appInfo)); holder.appName.setText(pm.getApplicationLabel(appInfo)); holder.packageName.setText(appInfo.packageName); return convertView; } } }