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
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;
}
}
}
