Android PackageManager：queryIntentActivities

        Intent intent = new Intent(Intent.ACTION_MAIN, null);
        intent.setPackage(getPackageName());
        intent.addCategory(Intent.CATEGORY_SAMPLE_CODE);

        PackageManager pm = getPackageManager();
        List<ResolveInfo> infos = pm.queryIntentActivities(intent, 0);

        ArrayList<SampleInfo> samples = new ArrayList<SampleInfo>();

        final int count = infos.size();
        for (int i = 0; i < count; i++) {
            final ResolveInfo info = infos.get(i);
            final CharSequence labelSeq = info.loadLabel(pm);
            String label = labelSeq != null ? labelSeq.toString() : info.activityInfo.name;

            Intent target = new Intent();
            target.setClassName(info.activityInfo.applicationInfo.packageName,
                    info.activityInfo.name);
            SampleInfo sample = new SampleInfo(label, target);
            samples.add(sample);
        }