Callback Listener in Unity - How to call script file method from UnityPlayerActivity in Android

Question

I have an android library project and imported the library project in the Unity project. Now, I want to implement a callback in Unity project, which will execute according to the response given by the android library project. I mean to say, Call Script File method from UnityPlayerActivity (Android Project).

Currently I am using below line of code but nothing happens:

UnityPlayer.UnitySendMessage("Main Camera","showMessage",errorMessage);

Main Camera is my Game Object. showMessage is message name in Script File. Message is message which will be displayed in Unity through Android Activity.

Please check my below code Unity Script File and Android Activity.

Unity Script File:

using UnityEngine;
using System.Collections;

public class scriptfile : MonoBehaviour {

    // Use this for initialization
    void Start () {


        AndroidJavaClass jc = new AndroidJavaClass("com.unity3d.player.UnityPlayer"); 
        AndroidJavaObject jo = jc.GetStatic<AndroidJavaObject>("currentActivity"); 
        jo.Call("shareText","236","236");
    }

    void showMessage(string message){
        print ("hello");
        Debug.Log ("hello");
    } 
}

Android File UnityPlayerActivity:

/**
 * Created by CH-E01073 on 28-09-2015.
 */
public class MainAct extends UnityPlayerActivity implements RegistrationListener,BOffersListener {
    Context context;
    SharedPreferences prefs ;
    String AppIds="";
    String PublisherIDs="";
     public void shareText(String AppId,String PublisherID) {
       context=MainAct.this;
        prefs = PreferenceManager
               .getDefaultSharedPreferences(context);
       Log.e("AppID", AppId);
       Log.e("PublisherID",PublisherID);

        AppIds=AppId;
        PublisherIDs=PublisherID;

         runOnUiThread(new Runnable() {
             @Override
             public void run() {
                 UnityPlayer.UnitySendMessage("Main Camera","showMessage","Start UI Thread");
                 if (prefs.getString(FreeBConstants.ID, null) == null
                         || prefs.getString(FreeBConstants.ID, null).equals("")
                         || !Build.VERSION.RELEASE.equals(prefs.getString(
                         FreeBConstants.VERSION, null))
                         || !FreeBCommonUtility.getDeviceId(context).equals(
                         (prefs.getString(FreeBConstants.DEVICE_ID, null)))) {
                BSDKLogger.enableLogging(true);
                SDKRegistration.initialize(MainAct.this, getApplicationContext(), AppIds,PublisherIDs);
                 }else{

                Offers Offers = new Offers(MainAct.this);
                 Offers.setOnFreeBOffersListener(MainAct.this);
                 Offers.setTitle(
                         "Pick Any Offer to unlock your premium features",
                         "#FFFFFF", "#FF6D00");
                 }
         }
         });



    }

    @Override
    public void onOffersLoaded(String code,String freeBOffers) {
        CommonUtility.showToast(getApplicationContext(), code);
        UnityPlayer.UnitySendMessage("Main Camera","showMessage",freeBOffers);
    }

    @Override
    public void onShowOffers() {

         UnityPlayer.UnitySendMessage("Main Camera","showMessage","Show Offers");
    }

    @Override
    public void noOfferInstalled(String s, String s2) {
    }

    @Override
    public void onLeaveApplication(String s, String s2) {
    }

    @Override
    public void onDialogDismiss(String s) {
    }

    @Override
    public void onOffersFailed(String code, String errorMessage) {

        FreeBCommonUtility.showToast(getApplicationContext(), errorMessage);
        UnityPlayer.UnitySendMessage("Main Camera","showMessage",errorMessage);
    }

    @Override
    public void onOffersInstallSuccess(String code, String errorMessage) {
         FreeBCommonUtility.showToast(getApplicationContext(), errorMessage);
    }

    @Override
    public void onOffersInstallFailure(String code, String errorMessage) {
         FreeBCommonUtility.showToast(getApplicationContext(), errorMessage);
    }


    @Override
    public void onRegistrationFailed(String code, String errorMessage) {
        FreeBCommonUtility.showToast(getApplicationContext(), errorMessage);
        UnityPlayer.UnitySendMessage("Main Camera","showMessage",errorMessage);
    }

    @Override
    public void onRegistrationSuccess(String code, String errorMessage) {
      // FreeBCommonUtility.showToast(getApplicationContext(), errorMessage);
        Log.e("SUCCESS", errorMessage);
        // TODO Auto-generated method stub
        UnityPlayer.UnitySendMessage("Main Camera","showMessage",errorMessage);

        Offers Offers = new Offers(MainAct.this);
        Offers.setOnFreeBOffersListener(MainAct.this);
       Offers.setTitle(
             "Pick Any Offer to unlock your premium features",
              "#FFFFFF", "#FF6D00");
    }
}

Can anyone help me to get rid of this issue?

Solution 1

Another option will be to implement an interface callback using AndroidJavaProxy. Instead of using UnitySendMessage, you can simply have an Interface callback in your java code and then implement this interface in C# using AndroidJavaProxy and pass it to the Java method in order to receive messages back.

Create your Java interface:

package com.example.android;
public interface PluginCallback {
    public void onSuccess(String videoPath);
    public void onError(String errorMessage);
}

Call the passed listener/callback to return messages

public void myPluginMethod(PluginCallback callback) {
    // Do something
    callback.onSuccess("onSuccess");
    // Do something horrible
    callback.onError("onError");
}

Implement the interface in C#

class AndroidPluginCallback : AndroidJavaProxy
    {
        public AndroidPluginCallback() : base("com.example.android.PluginCallback") { }

        public void onSuccess(string videoPath) {
            Debug.Log("ENTER callback onSuccess: " + videoPath);
        }
        public void onError(string errorMessage)
        {
            Debug.Log("ENTER callback onError: " + errorMessage);
        }
    }

Pass the C# interface to the Java method

AndroidJavaObject pluginClass = new     AndroidJavaObject("com.example.android.MyPlugin");
pluginClass.Call("myPluginMethod", new AndroidPluginCallback());

Solution 2

I believe you are only allowed to call UnitySendMessage() from the main thread - at least in one scenario above you are calling it from the Android UI worker thread.

As a quick sanity test, try calling it before you right at the top of your shareText() function.

Comments

[Vivek]

Make sure your script attached with Main Camera (Gameobject which is called). see ref answers.unity3d.com/questions/366452/…

[user1986760]

yes vivek, its already attached correctly.

[Ori Frish]

I personally don't like the Unity messaging system, why not using an interface for callback?

[user1986760]

is there no way to implement interfaces for communicating between android to unity. Exactly, interface is nice idea if we want to communicate within the unity or within the android modules. Here we want to create bridge between Android Activity to Unity Script File.

[Guney Ozsan]

My class needs to be AppCompatActivity. And I'm getting an error AndroidJavaException: java.lang.IllegalStateException: Method addObserver must be called on the main thread. I tried things like runOnUiThread(new Runnable() { @Override public void run() { callback.onSuccess("Some message"); }, but could not make it work. Any ideas?