android 列出所有的应用
在android中实现一个像桌面那样把所有应用都列举出来。用GridView来实现显示。
主要代码如下：
先修改main.xml文件：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<GridView
android:id="@+id/gridView"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
</LinearLayout>
然后创建一个xml文件来显示你想在GridView中显示的格式，我这边是用一个图标加一个文件来显示的。
application.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <ImageView android:id="@+id/icon" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <TextView android:id="@+id/title" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </LinearLayout>
package com.mzz;
import java.util.Collections;
import java.util.List;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;
public class ListApplications extends Activity implements OnItemClickListener{
private GridView mGridView = null ;
private PackageManager mPackageManager = null ;
private List<ResolveInfo> mAllApps = null ;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
showView();
}
public void showView() {
mPackageManager = getPackageManager();
mGridView = (GridView)findViewById(R.id.gridView);
getAllApps();
mGridView.setAdapter(new MyAdapter(ListApplications.this , mAllApps));
mGridView.setNumColumns(3);//每行显示3个
mGridView.setOnItemClickListener(this);
}
public void getAllApps() {
//设置一个Intent的action和category为需要显示
Intent intent = new Intent(Intent.ACTION_MAIN , null);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
//如何条件的查出来
mAllApps = mPackageManager.queryIntentActivities(intent, 0);
//排序
Collections.sort(mAllApps, new ResolveInfo.DisplayNameComparator(mPackageManager));
}
//当点击gridview中的图标时，进入相应的应用
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
// TODO Auto-generated method stub
ResolveInfo res = mAllApps.get(position);
//得到该应用的包名和activity
String pkg = res.activityInfo.packageName ;
String cls = res.activityInfo.name ;
ComponentName mComponentName = new ComponentName(pkg, cls);
Intent intent = new Intent();
intent.setComponent(mComponentName);
startActivity(intent);
}
//Adapter
class MyAdapter extends BaseAdapter {
private Context mContext ;
private List<ResolveInfo> mAllApps ;
MyAdapter(Context context , List<ResolveInfo> allApps) {
mContext = context ;
mAllApps = allApps ;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return mAllApps.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return null;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
convertView = LayoutInflater.from(mContext).inflate(R.layout.applications, null);
ImageView icon = (ImageView)convertView.findViewById(R.id.icon);
TextView title = (TextView)convertView.findViewById(R.id.title);
ResolveInfo res = mAllApps.get(position);
icon.setImageDrawable(res.loadIcon(mPackageManager));
title.setText(res.loadLabel(mPackageManager));
return convertView;
}
}
}
到这里代码的全部编写完成了。
效果如下图所见:
虽然和本身的显示相比，我的这个有点丑。没有处理图标的大小，不过功能上实现了。当你点击相应的图标的时候，会进入相应的应用的主Activity。
呵呵。。。