Calling an Android method from Unity

Hello All,

I followed the link here http://unity3d.com/support/documentation/Manual/Android-Integrating Unity With Eclipse.html to integrate eclipse and unity.

I am successfully able to run an unity from eclipse.

What I really want to do is I have a button in Unity interface. And when that button is pressed, I want to call a function foo() in Android Activity.

But the problem is I cannot call this function inside android Activity . My code is as follows

Android:

Code (csharp):

1. public class MainActivity extends UnityPlayerActivity {
2.     /** Called when the activity is first created. */
3.     @Override
4.     public void onCreate(Bundle savedInstanceState) {
5.         super.onCreate(savedInstanceState);
6.     }
7.    
8.    // call this method from unity
9.     public static void foo(){
10.         Log.d("TEST","Foo method is called is called");  // this method is never called
11.        
12.     }
13. }

And in Unity cSharp script in button press handler my code is

Code (csharp):

1.  
2.  
3. if(GUI.Button(new Rect(20,70,80,20), "Call Android Method")) {
4.  
5.         using (AndroidJavaClass cls_UnityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer")) {
6.  
7.             using (AndroidJavaObject obj_Activity = cls_UnityPlayer.GetStatic<AndroidJavaObject>("currentActivity")) {
8.  
9.                 AndroidJavaClass cls_MainActivity = new AndroidJavaClass("com.me.callActivity.MainActivity");
10.  
11.                 cls_MainActivity.CallStatic("Init", obj_Activity);
12.  
13.                 cls_MainActivity.CallStatic("foo");
14.                
15.  
16.             }
17. }
18.  
19.  

My applilcation doesn't crash. But when i see the log in eclipse i get the JNI error

JNI: Unable to find method id for 'foo' (static)

Am I missing something? Do I have to do manually as described in
http://randomactsofdev.wordpress.com/2011/08/19/accessing-the-android-compass-through-unity-3d/

Thank you,
BlackDiamond

 

I think you've got one step too many in there. The current activity which you're getting is the main activity so you should be using that to call your methods.

Try:

Code (csharp):

1.  
2. if(GUI.Button(new Rect(20,70,80,20), "Call Android Method"))
3. {
4.     using (AndroidJavaClass cls_UnityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
5.     {
6.         using (AndroidJavaObject obj_Activity = cls_UnityPlayer.GetStatic<AndroidJavaObject>("currentActivity"))
7.         {
8.             obj_Activity .CallStatic("foo");
9.         }
10.     }
11. }
12.  

 

Hello HazeTI,

I did as you said and it works now.


Thank you,
BlackDiamond

 

My issue is that I need to call startActivity in foo function (switch from unity view to another activity android). I can get context by passing parameter obj_Activity from unity to foo funtion

Code (csharp):

1. using (AndroidJavaClass cls_UnityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer")) {
2.             using (AndroidJavaObject obj_Activity = cls_UnityPlayer.GetStatic<AndroidJavaObject>("currentActivity")) {
3.                 AndroidJavaClass cls_MainActivity = new AndroidJavaClass("com.example.TestActivity");
4.                 cls_MainActivity.CallStatic("foo", obj_Activity);
5.             }
6.         }

In foo function, my code is

Code (csharp):

1. public static void foo(Context c){
2.         Intent intent = c.getPackageManager().getLaunchIntentForPackage("com.example.NextActivity");       
3.         c.startActivity(intent);
4.     }

It cause errors

Code (csharp):

1. AndroidJavaException: java.lang.NullPointerException
2. at UnityEngine.AndroidJNISafe.CheckException () [0x00000] in <filename unknown>:0
3. ...
4.  

It seems like it cannot find package name. Can anyone help me?

 

Anybody can help? I really need this!

 

Anyway, I have found solution. It is no need to implement java file and add it in Plugins/Android like this tutorial http://randomactsofdev.wordpress.com/2011/08/19/accessing-the-android-compass-through-unity-3d/

You just make an activity A extends UnityPlayerActivity and add meta code in that activity in AndroidManifest.xml

Code (csharp):

1. <meta-data
2.                 android:name="unityplayer.ForwardNativeEventsToDalvik"
3.                 android:value="false" />

If you want to call method in android from unity, simply declare these static method in activity A

Here is my simple Unity project and Android project. My Android project has 3 activities switch between Android and Unity: WelcomeActivity (Android) <-> MainActivity (Unity) <-> PhotoActivity (Android). My Unity project has a cube moving around with two next and back button to switch screen.
http://www.mediafire.com/download/ejfjsega9cdqxdm/UnityAndroidIntegration.zip

Some useful tutorial here
http://www.rbcafe.com/Softwares/Unity/Documentation/Manual/Android-Launch%20an%20Android%20Application%20from%20a%20Unity%20Application.html

 

I'm sorry for the wrong source code uploaded. This is a new version has been tested
http://www.mediafire.com/download/wdbcmx3iczl924a/UnityAndroidIntegration_updated.zip

 

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