Using admob rewarded ad in unity singleton pattern - unity3d

Question

I am using admob ads in my app and they are working fine. But when i try to do something after a ad close or reward earned call back my code breaks. Following is my adMob script
public class AdMobScript : MonoBehaviour
{
...
public event Action OnReviveRewardEarned;
public event Action OnReviveAdLoaded;
public event Action OnReviveAdClosed;
private void LoadReviveRewardedAd()
{
reviveRewardedAd = new RewardedAd(adReviveRewardedId);
reviveRewardedAd.OnAdLoaded += ReviveAdLoaded;
reviveRewardedAd.OnUserEarnedReward += ReviveEarnedReward;
reviveRewardedAd.OnAdClosed += ReviveAdClosed;
AdRequest request = new AdRequest.Builder().Build();
reviveRewardedAd.LoadAd(request);
}
private void ReviveAdClosed(object sender, EventArgs e)
{
LoadReviveRewardedAd();
if (isRewardErned)
{
isRewardErned = false;
OnReviveRewardEarned.Invoke();
}
else
OnReviveAdClosed.Invoke();
}
private void ReviveEarnedReward(object sender, Reward e)
{
isRewardErned = true;
}
private void ReviveAdLoaded(object sender, EventArgs e)
{
//reviveButton.interactable = true;
OnReviveAdLoaded.Invoke();
}
public void ShowAdToRevive()
{
if (reviveRewardedAd.IsLoaded())
{
reviveRewardedAd.Show();
}
}
...
}
In the callbacks i am calling my adManager script which is in term using adMob script. Here is the code for it.
public class AdManager : MonoBehaviour
{
...
private void Start() {
AdMobScript.instance.OnReviveAdClosed += ReviveAdClosed;
AdMobScript.instance.OnReviveAdLoaded += ReviveAdLoaded;
AdMobScript.instance.OnReviveRewardEarned += ReviveReward;
}
#region ReviveAds
private void ReviveReward() {
//game crash here
backButton.gameObject.SetActive(true);
reviveButton.gameObject.SetActive(false);
noThanksButton.gameObject.SetActive(false);
manager.Revive();
}
private void ReviveAdLoaded() {
reviveButton.interactable = true;
}
private void ReviveAdClosed() {
//game crash here
reviveButton.interactable = false;
}
public void ShowAdToRevive() {
AdMobScript.instance.ShowAdToRevive();
}
...
}
After either ad close or reward earned my game crashes (error log says
get_gameObject can only be called from the main thread
). There must be something i am doing wrong. Can anyone please point me to the right direction?

Answer 1

The reason for the problem - you trying to manipulate with MonoBehaviors, not in main thread.
Just write simple scheduler which calls the events in the Unity thread, like this:
Scheduler:
using System;
using UnityEngine;
public class Scheduler : MonoBehaviour
{
public static Scheduler instance;
public event Action secondTick = delegate { };
private float seconds = 0;
private void Awake()
{
instance = this;
}
private void Update()
{
seconds += Time.unscaledDeltaTime;
if (seconds >= 1.0f)
{
seconds -= 1.0f;
secondTick.Invoke();
}
}
}
Updated AdMobScript:
public class AdMobScript : MonoBehaviour
{
...
private bool onRewardEarnedCall = false;
private bool onRewardAdLoaded = false;
private bool onRewardAdClosed = false;
public event Action OnReviveRewardEarned;
public event Action OnReviveAdLoaded;
public event Action OnReviveAdClosed;
private void LoadReviveRewardedAd()
{
reviveRewardedAd = new RewardedAd(adReviveRewardedId);
reviveRewardedAd.OnAdLoaded += ReviveAdLoaded;
reviveRewardedAd.OnUserEarnedReward += ReviveEarnedReward;
reviveRewardedAd.OnAdClosed += ReviveAdClosed;
AdRequest request = new AdRequest.Builder().Build();
reviveRewardedAd.LoadAd(request);
Scheduler.instance.secondTick += OnSecondTick;
}
private void OnSecondTick()
{
if(onRewardAdClosed)
{
onRewardAdClosed = false;
OnReviveAdClosed.Invoke();
}
if(onRewardEarnedCall)
{
OnReviveRewardEarned.Invoke();
onRewardEarnedCall = false;
}
if(onRewardAdLoaded)
{
OnReviveAdLoaded.Invoke();
onRewardAdLoaded = false;
}
}
private void ReviveAdClosed(object sender, EventArgs e)
{
LoadReviveRewardedAd();
if (isRewardErned)
{
isRewardErned = false;
onRewardEarnedCall = true;
}
else
onRewardAdClosed = true;
}
private void ReviveEarnedReward(object sender, Reward e)
{
isRewardErned = true;
}
private void ReviveAdLoaded(object sender, EventArgs e)
{
//reviveButton.interactable = true;
onRewardAdLoaded = true;
}
public void ShowAdToRevive()
{
if (reviveRewardedAd.IsLoaded())
{
reviveRewardedAd.Show();
}
}
...
}
This is a very simple and not optimize solution but this will solve your problem.