读取非系统软件安装包

推荐安卓开发神器（里面有各种UI特效和android代码库实例）

if (filterOption == FILTER_APPS_THIRD_PARTY) {
            List<ApplicationInfo> appList =new ArrayList<ApplicationInfo> ();
            for (ApplicationInfo appInfo : installedAppList) {
                boolean flag = false;
                if ((appInfo.flags & ApplicationInfo.FLAG_UPDATED_SYSTEM_APP) != 0) {
                    // Updated system app
                    flag = true;
                } else if ((appInfo.flags & ApplicationInfo.FLAG_SYSTEM) == 0) {
                    // Non-system app
                    // 通过 FLAG 标记是否系统软件
                    flag = true;
                }
                if (flag) {
                    appList.add(appInfo);
                }
            }
            return appList;
}