我们手机上安装的应用默认是以GridView的形式排放的,本篇博客将讲述以ListView的形式获得所有应用,并且点击应用后可以启动。
1.
ListView item的布局文件 list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="48dp"
android:padding="5dip"
>
<ImageView
android:id="@+id/ivIcon"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginRight="5dip"
android:scaleType="center"/>
<LinearLayout
android:orientation="vertical"
android:layout_width="0dip"
android:layout_height="match_parent"
android:layout_weight="1">
<TextView
android:id="@+id/tvName"
android:layout_width="match_parent"
android:layout_height="0dip"
android:layout_weight="1"
android:gravity="center_vertical"/>
<TextView
android:id="@+id/tvPack"
android:layout_width="match_parent"
android:layout_height="0dip"
android:layout_weight="1"
android:singleLine="true"
android:ellipsize="marquee"/>
</LinearLayout>
</LinearLayout>
2.主布局文件activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<ListView
android:id="@+id/lvApps"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
3.ListView的适配器AppInfoAdapter.java
public class AppInfoAdapter extends BaseAdapter {
private Context mContext;
private List mListApp;
private LayoutInflater mLayoutInflater;
private PackageManager mPackageManager;
public AppInfoAdapter(Context mContext, List mListApp, PackageManager mPackageManager) {
this.mContext = mContext;
this.mListApp = mListApp;
this.mPackageManager = mPackageManager;
this.mLayoutInflater = LayoutInflater.from(mContext);
}
@Override
public int getCount() {
return mListApp.size();
}
@Override
public Object getItem(int position) {
return mListApp.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ApplicationInfo appInfo = (ApplicationInfo) mListApp.get(position);
ViewHolder holder = null;
if(convertView == null){
holder = new ViewHolder();
convertView = mLayoutInflater.inflate(R.layout.list_item, null);
holder.ivAppIcon = (ImageView) convertView.findViewById(R.id.ivIcon);
holder.tvAppName = (TextView) convertView.findViewById(R.id.tvName);
holder.tvPackageName = (TextView) convertView.findViewById(R.id.tvPack);
convertView.setTag(holder);
}else{
holder = (ViewHolder) convertView.getTag();
}
holder.ivAppIcon.setImageDrawable(appInfo.loadIcon(mPackageManager));
holder.tvAppName.setText(appInfo.loadLabel(mPackageManager));
holder.tvPackageName.setText(appInfo.packageName);
return convertView;
}
static class ViewHolder{
ImageView ivAppIcon;
TextView tvAppName;
TextView tvPackageName;
}
}
4.工具类 Utils.java
public class Utils {
/**
* 获取已安装的应用
* @param context
* @return
*/
public static List getInstalledApp(Context context){
return context.getPackageManager().getInstalledApplications(PackageManager.GET_META_DATA);
}
/**
* 根据包名,启动应用
* @param context
* @param pm
* @param packageName
* @return
*/
public static boolean launchApp(Context context,PackageManager pm,String packageName){
Intent intent = pm.getLaunchIntentForPackage(packageName);
if(intent != null){
try {
context.startActivity(intent);
return true;
} catch (ActivityNotFoundException e) {
Toast.makeText(context, "Applicatin not found", Toast.LENGTH_SHORT).show();
e.printStackTrace();
}
}
return false;
}
}
5.MainActivity.java
public class MainActivity extends Activity {
private ListView mListView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mListView = (ListView) findViewById(R.id.lvApps);
AppInfoAdapter adapter = new AppInfoAdapter(this, Utils.getInstalledApp(this), getPackageManager());
mListView.setAdapter(adapter);
mListView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
ApplicationInfo info = (ApplicationInfo) parent.getItemAtPosition(position);
Utils.launchApp(parent.getContext(), getPackageManager(), info.packageName);
}
});
}
}
运行截图: