Android Appの初回起動または更新または初回起動

try {
    PackageInfo info = getPackageManager().getPackageInfo(PACKAGE_NAME,0);
    //     versionCode
    int versionCode = info.versionCode;
    SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
    //      lastVersion
    int lastVersion = preferences.getInt(VERSION_CODE, 0);
    /**
     *                ，   App      ；          
      */

    if (versionCode>lastVersion){
       //         App                    


        preferences.edit().putInt(VERSION_CODE,versionCode).commit();
    }
} catch (PackageManager.NameNotFoundException e) {
    e.printStackTrace();
}