获取Android手机所以应用程序并开启

           网上很多阐明如果在一个应用程序中开启另一个应用的例子，如下

   

Android应用程序中启动另一个应用程序

2

3	Intent intent=new Intent();

4	intent.setComponent(new ComponentName("com.Android.calendar","com.android.calendar.LaunchActivity"));

5	startActivity(intent);

  很显然这样局限性太大，因为我们在程序中只能获得其他应用的包名，而不能获取到它的主Activity的名称（起码我是不会），所以这样就很难将之应用到项目中来，那有没有一种不需要知道主Activity名就能打开其他应用程序的方法呢？我找了一下，确实有， 参考 文章：http://www.pocketdigi.com/20110728/427.html 

下面用一个很简单的例子例子来阐述：

             程序界面只有一个ListView，xml文件就不写了。。、

 Activity

package com.gqs.getapp;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import android.app.Activity;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ImageView;
import android.widget.ListView;

public class GetAllAppActivity extends Activity {
	private ListView lv;
	private ArrayList<HashMap<String, Object>> list = new ArrayList<HashMap<String, Object>>();
	private AppListAdapter adapter;
	PackageManager pckMan;

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		initUI();
		initData();
		lv.setOnItemClickListener(new OnItemClickListener() {

			@Override
			public void onItemClick(AdapterView<?> parent, View view,
					int position, long id) {
				// TODO Auto-generated method stub

				Intent intent = pckMan.getLaunchIntentForPackage(parent
						.getAdapter().getItem(position).toString());

                               if(intent!=null)
				startActivity(intent);
			}
		});
	}

	public void initUI() {
		lv = (ListView) findViewById(R.id.listView);
		adapter = new AppListAdapter(this, list);
		lv.setAdapter(adapter);
	}

	public void initData() {

//最好异步加载，为减少代码量，此处皆在主线程做了处理
		pckMan = getPackageManager();
		List<PackageInfo> packs = pckMan.getInstalledPackages(0);
		int count = packs.size();
		for (int i = 0; i < count; i++) {
			PackageInfo p = packs.get(i);
			if (p.versionName == null) {
				continue;
			}
			// 判断该软件包是否在/data/app目录下
			HashMap<String, Object> map = new HashMap<String, Object>();
			ApplicationInfo appInfo = p.applicationInfo;
			String pName = p.applicationInfo.packageName;
			map.put("pName", p.applicationInfo.packageName);
				map.put("icon", p.applicationInfo.loadIcon(pckMan));
			map.put("appName", p.applicationInfo.loadLabel(pckMan).toString());
			list.add(map);
			if ((appInfo.flags & ApplicationInfo.FLAG_SYSTEM) > 0) {
				// 系统程序
				// name = p.applicationInfo.loadLabel(pckMan).toString();
				Log.i(" 系统程序app name==", pName);
			} else {
				// 不是系统程序
				// String pName = p.applicationInfo.packageName;
				// name = p.applicationInfo.loadLabel(pckMan).toString();
				Log.i(" 不是系统程序app name==", pName);
			}
		}
	}
}

package com.gqs.getapp;

import java.util.ArrayList;
import java.util.HashMap;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

/**
 * @author gqs
 * @version 创建时间：2012-8-13 上午3:21:31 类说明
 */

public class AppListAdapter extends BaseAdapter {

	private ArrayList<HashMap<String, Object>> list;
	private LayoutInflater inlfater;

	public AppListAdapter(Context context,
			ArrayList<HashMap<String, Object>> list) {
		this.list = list;
		inlfater = LayoutInflater.from(context);
	}

	@Override
	public int getCount() {
		// TODO Auto-generated method stub
		return list.size();
	}

	@Override
	public Object getItem(int position) {
		// TODO Auto-generated method stub
		return list.get(position).get("pName");
	}

	@Override
	public long getItemId(int position) {
		// TODO Auto-generated method stub
		return position;
	}

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		// TODO Auto-generated method stub
		//此处未优化
		convertView = inlfater.inflate(R.layout.item, null);
		TextView tv = (TextView) convertView.findViewById(R.id.tvAppName);
		ImageView iv = (ImageView) convertView.findViewById(R.id.ivIcon);
		tv.setText(list.get(position).get("appName").toString());
		iv.setImageDrawable((Drawable) list.get(position).get("icon"));
		return convertView;
	}

}

  注：1.程序不需什么权限

        2.并不所以程序都可以打开的