Q:

Creating custom button class in Android

I'm trying to create custom button class for my android app 
public class TicTacButton extends Button 

I've set all the constructors inside the TicTacButton and created custom methods and properties. In my main activity, I've tried to initialize the Buttons as 
TicTacButton btn = (TicTacButton) findViewById(R.id.button1);

I'm getting a 

java.castClassException. android.widget.Button cannot be cast to
  com.example.tictactoetitan.TicTacButton

I tried changing my xml file as 
<TicTacButton
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/button1"
        android:layout_toRightOf="@+id/button1" />

It didn't work.

A:

Using the full package name in the XML file fixed it.
<com.example.tictactoetitan.TicTacButton
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/button1"
        android:layout_toRightOf="@+id/button1" />

