frida-java-bridge | Java runtime interop from Frida | Wrapper library

You are trying to hook the wrong class - most likely because you are using Jadx for decompiling the wrong settings and no knowledge on Java classes.

If you are using Jadx for decompiling the APK file make sure to disable the setting Inline anonymous classes to see the real class name a method belongs to.

The Method onClick() belongs to the anonymous inner class created by new DialogInterface.OnClickListener() and not to sg.vantagepoint.uncrackable1.MainActivity - hence you are trying to hook the wrong class. The method a(String) it is used in is totally irrelevant for hooking. Anonymous inner classes have their own class name based on the outer class appended by $ and a number. Therefore the correct class name may be sg.vantagepoint.uncrackable1.MainActivity$1 or sg.vantagepoint.uncrackable1.MainActivity$2, depending on how many other anonymous inner classes are present.

Additionally something like mClass.a.onClick is not possible, as there is no method inside a method (a is a method and onClick is a method).

In the end you may end up with the following frida code:

jadx deobfuscates variable names to make code readable. You have to use original name of member to access it.

So you need to use names "a" and "d" to access those variables: