Error call function from android plugin when Java class extends Activity

Hello guys .

I am programming custom android plugin and i want to call functions (static and non-static) from the plugin .
when i call the function in c# (code bellow) from normal java class (that doesn't extends any other class) inside the JAR plugin file every thing is working perfect

Code (csharp):

1.  
2. using (AndroidJavaObject cls = new AndroidJavaObject("com.BlackSowrd.androidplugin.AndroidController"))
3.                 {
4.                     if (cls != null)
5.                     {
6.                         cls.Call("ShowAlert");
7.                     }
8.                 }
9.  

But the problem occur when i make the java class extends Activity and try to call function using AndroidJavaObject , it throws exception


Java.lang.RuntimeException : Can't create handler inside thread that has not called Looper.prepare()

I searched for solution for that but i did not able to solve this issue , Please guys I need help .

 

Thanks bittter for the fast replay i really appreciate it.

I added new class for my android plugin which doesn't extend Activity class and it works fine I can call any function inside that class in unity but, I tried to start activity from this class and it did not worked. it gives me this exception from the unity side

Java.lang.ClassNotFoundException : com.BlackSowrd.AndroidPlugin.MainActivity

I also tried using the AndroidJavaRunnable and it also execute without any exceptions but it did not call the java function (From java class which extends Activity) and this is how i did it

Code (csharp):

1.  
2.                 AndroidJavaClass unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
3.                 AndroidJavaObject activity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity");
4.                 activity.Call("runOnUiThread", new AndroidJavaRunnable(runOnUiThread));
5.  
6.  
7.     void runOnUiThread()
8.     {
9.         using (AndroidJavaObject cls = new AndroidJavaObject("com.BlackSowrd.AndroidPlugin.MainActivity"))
10.         {
11.             if (cls != null)
12.             {
13.                 cls.Call("ShowAlert");
14.             }
15.         }
16.     }
17.  

I also read the link for the android developer and it make many things clear for me . but i don't know how i am gonna solve it :cry:
can you please explain in more details with code please.