下面是使用PackageManager的一种更简洁的方式

final PackageManager pm = getPackageManager();
//get a list of installed apps.
List<ApplicationInfo> packages = pm.getInstalledApplications(PackageManager.GET_META_DATA);

for (ApplicationInfo packageInfo : packages) {
    Log.d(TAG, "Installed package :" + packageInfo.packageName);
    Log.d(TAG, "Source dir : " + packageInfo.sourceDir);
    Log.d(TAG, "Launch Activity :" + pm.getLaunchIntentForPackage(packageInfo.packageName)); 
}
// the getLaunchIntentForPackage returns an intent that you can use with startActivity() 

更多信息请点击这里http://qtcstation.com/2011/02/how-to-launch-another-app-from-your-app/

另一种过滤系统应用程序的方法(适用于king9981的例子):

/**
 * Return whether the given PackageInfo represents a system package or not.
 * User-installed packages (Market or otherwise) should not be denoted as
 * system packages.
 * 
 * @param pkgInfo
 * @return
 */
private boolean isSystemPackage(PackageInfo pkgInfo) {
    return ((pkgInfo.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0);
}

这里有一个很好的例子:

class PInfo {
    private String appname = "";
    private String pname = "";
    private String versionName = "";
    private int versionCode = 0;
    private Drawable icon;
    private void prettyPrint() {
        Log.v(appname + "\t" + pname + "\t" + versionName + "\t" + versionCode);
    }
}

private ArrayList<PInfo> getPackages() {
    ArrayList<PInfo> apps = getInstalledApps(false); /* false = no system packages */
    final int max = apps.size();
    for (int i=0; i<max; i++) {
        apps.get(i).prettyPrint();
    }
    return apps;
}

private ArrayList<PInfo> getInstalledApps(boolean getSysPackages) {
    ArrayList<PInfo> res = new ArrayList<PInfo>();        
    List<PackageInfo> packs = getPackageManager().getInstalledPackages(0);
    for(int i=0;i<packs.size();i++) {
        PackageInfo p = packs.get(i);
        if ((!getSysPackages) && (p.versionName == null)) {
            continue ;
        }
        PInfo newInfo = new PInfo();
        newInfo.appname = p.applicationInfo.loadLabel(getPackageManager()).toString();
        newInfo.pname = p.packageName;
        newInfo.versionName = p.versionName;
        newInfo.versionCode = p.versionCode;
        newInfo.icon = p.applicationInfo.loadIcon(getPackageManager());
        res.add(newInfo);
    }
    return res; 
}

如果在一个包中有多个启动器，上述代码就有问题。例如:在LG Optimus Facebook为LG, MySpace为LG, Twitter为LG包含在一个包的名称SNS，如果你使用上述SNS将重复。经过几个小时的研究，我得到了以下代码。看起来效果不错。

private List<String> getInstalledComponentList()
            throws NameNotFoundException {
        final Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);
        mainIntent.addCategory(Intent.CATEGORY_LAUNCHER);
        List<ResolveInfo> ril = getPackageManager().queryIntentActivities(mainIntent, 0);
        List<String> componentList = new ArrayList<String>();
        String name = null;

        for (ResolveInfo ri : ril) {
            if (ri.activityInfo != null) {
                Resources res = getPackageManager().getResourcesForApplication(ri.activityInfo.applicationInfo);
                if (ri.activityInfo.labelRes != 0) {
                    name = res.getString(ri.activityInfo.labelRes);
                } else {
                    name = ri.activityInfo.applicationInfo.loadLabel(
                            getPackageManager()).toString();
                }
                componentList.add(name);
            }
        }
        return componentList;
    }

context.getPackageManager () .getInstalledApplications (PackageManager.GET_META_DATA); 应该返回所有已安装应用程序的列表，但在android 11中，它只返回系统应用程序的列表。要获得所有应用程序(系统+用户)的列表，我们需要为应用程序提供额外的权限

< uses-permission android: name = " android.permission.QUERY_ALL_PACKAGES " / >

干净的解决方案，过滤成功的系统应用程序

这个解决方案背后的思想是，每个系统应用程序的主活动都没有一个自定义的活动图标。这个方法给了我一个很好的结果:

 public static Set<PackageInfo> getInstalledApps(Context ctx) {
    final PackageManager packageManager = ctx.getPackageManager();

    final List<PackageInfo> allInstalledPackages = packageManager.getInstalledPackages(PackageManager.GET_META_DATA);
    final Set<PackageInfo> filteredPackages = new HashSet();

    Drawable defaultActivityIcon = packageManager.getDefaultActivityIcon();

    for(PackageInfo each : allInstalledPackages) {
        if(ctx.getPackageName().equals(each.packageName)) {
            continue;  // skip own app
        }

        try {
            // add only apps with application icon
            Intent intentOfStartActivity = packageManager.getLaunchIntentForPackage(each.packageName);
            if(intentOfStartActivity == null)
                continue;

            Drawable applicationIcon = packageManager.getActivityIcon(intentOfStartActivity);
            if(applicationIcon != null && !defaultActivityIcon.equals(applicationIcon)) {
                filteredPackages.add(each);
            }
        } catch (PackageManager.NameNotFoundException e) {
            Log.i("MyTag", "Unknown package name " + each.packageName);
        }
    }

    return filteredPackages;
}