在網上搜尋了一會相關的實作代碼,發現所有的文章都說是需要包名和類名。但是人家的程式,我們怎麼可能知道哪個是第一個啟動的Activity?是以,真正用在項目上,那種方法基本上沒什麼用的。于是檢視官方文檔,發現這樣一個方法:
public abstract Intent getLaunchIntentForPackage (String packageName)
英文原文:Return a “good” intent to launch a front-door activity in a package, for use for example to implement an “open” button when browsing through packages.大概意思就是傳回一個程式入口的Intent,就是Java程式的Main方法。
這下簡單了,直接startActivity(傳回的intent)即可。
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.AdapterView.OnItemClickListener;
public class Main extends Activity {
/** Called when the activity is first created. */
ListView lv;
Adapter adapter;
ArrayList<HashMap<String, Object>> items = new ArrayList<HashMap<String, Object>>();
PackageManager pm;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
lv = (ListView) findViewById(R.id.lv);
final PackageManager pm = getPackageManager();
// 得到PackageManager對象
List<PackageInfo> packs = pm
.getInstalledPackages(PackageManager.GET_UNINSTALLED_PACKAGES);
// 得到系統 安裝的所有程式包的PackageInfo對象
for (PackageInfo pi : packs) {
HashMap<String, Object> map = new HashMap<String, Object>();
map.put("icon", pi.applicationInfo.loadIcon(pm));
// 圖示
map.put("appName", pi.applicationInfo.loadLabel(pm));
// 應用名
map.put("packageName", pi.packageName);
// 包名
items.add(map);
// 循環讀取存到HashMap,再增加到ArrayList.一個HashMap就是一項
}
adapter = new Adapter(this, items, R.layout.piitem, new String[] {
"icon", "appName", "packageName" }, new int[] { R.id.icon,
R.id.appName, R.id.packageName });
// 參數:Context,ArrayList(item的集合),item的layout,包含ArrayList中Hashmap的key的數組,key所對應的值相對應的控件id
lv.setAdapter(adapter);
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// TODO Auto-generated method stub
String packageName = (String) items.get(position).get(
"packageName");
//取到點選的包名
Intent i = pm.getLaunchIntentForPackage(packageName);
//如果該程式不可啟動(像系統自帶的包,有很多是沒有入口的)會傳回NULL
if (i != null)
startActivity(i);
}
});
}
}