private void OnGUI()
    {
        if (GUI.Button(new Rect(500, 500, 300, 150), "谷歌商店"))
        {
            openAPPinMarket(Application.identifier);
        }

        if (GUI.Button(new Rect(500, 900, 300, 150), "Facebook"))
        {
            OpenFacebook();
        }
    }

    
    /// <summary>
    /// 跳轉到應用商店
    /// </summary>
    private void openAPPinMarket(string appid)
    {

#if UNITY_ANDROID
        //init AndroidJavaClass
        AndroidJavaClass UnityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"); ;
        AndroidJavaClass Intent = new AndroidJavaClass("android.content.Intent");
        AndroidJavaClass Uri = new AndroidJavaClass("android.net.Uri");

        // get currentActivity
        AndroidJavaObject currentActivity = UnityPlayer.GetStatic<AndroidJavaObject>("currentActivity");

        AndroidJavaObject jstr_content = new AndroidJavaObject("java.lang.String", "market://details?id=" + appid);

        AndroidJavaObject intent = new AndroidJavaObject("android.content.Intent", Intent.GetStatic<AndroidJavaObject>("ACTION_VIEW"), Uri.CallStatic<AndroidJavaObject>("parse", jstr_content));

        currentActivity.Call("startActivity", intent);
#endif
    }
    
       /// <summary>
    /// 跳轉到facebook
    /// </summary>
    private void OpenFacebook()
    {
        if (JudgeHaveApp("com.facebook.katana"))
            Application.OpenURL("fb://page/331347397603096/");
        else
            Application.OpenURL("https://www.facebook.com/deliciousio");
    }

    /// <summary>
    /// 判斷手機是否有改app
    /// </summary>
    private bool JudgeHaveApp(string pageName)
    {
        AndroidJavaClass up = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
        AndroidJavaObject ca = up.GetStatic<AndroidJavaObject>("currentActivity");
        AndroidJavaObject packageManager = ca.Call<AndroidJavaObject>("getPackageManager");
        AndroidJavaObject appList = packageManager.Call<AndroidJavaObject>("getInstalledPackages", 0);
        int num = appList.Call<int>("size");
        for (int i = 0; i < num; i++)
        {
            AndroidJavaObject appInfo = appList.Call<AndroidJavaObject>("get", i);
            string packageNew = appInfo.Get<string>("packageName");
            if (packageNew.CompareTo(pageName) == 0)
            {
                return true;
            }
        }
        return false;
    }
 

跳轉應用商店那個會讓使用者選擇使用哪個應用商店

判斷是否有該app的包名從谷歌商店搜尋該應用

id=  後面這些就是包名