获取版本号

    /**
     * 获取版本号
     * */
    public static String getLocalVersionName(Context ctx) {
        String localVersion = "";
        try {
            PackageInfo packageInfo = ctx.getApplicationContext()
                    .getPackageManager()
                    .getPackageInfo(ctx.getPackageName(), 0);
            localVersion = packageInfo.versionName;
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
        return localVersion;
    }