BOTJr.:

I am new to android, so , i have been playing with fragments to understand how they work.

Firstly, i made a calciKeyboard class which extends Fragment

Code:

public class calciKeyboard extends Fragment {
    @Nullable
    Button b;

    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {

        GridLayout gridLayout=(GridLayout) inflater.inflate(R.layout.calci_keyboard,container,false);
        for(int i=0;i            b=(Button)gridLayout.getChildAt(i);
            if (b != null) {
                b.setBackground(getResources().getDrawable(R.drawable.button_dark_gradient));
            }
        }
        return gridLayout;
    }
}

calciKeyboard.xml

    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:rowCount="4"
    android:columnCount="4"
    >
    Buttons inside....

advance_mix

public class advance_mix extends Activity {
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.advance_length);
    }
}

advance_length

    android:layout_width="match_parent"
    android:layout_height="match_parent">

        android:layout_height="wrap_content"
        android:name="com.example.tilak.myfirstapplication.calciKeyboard"
        android:id="@+id/calciKeyboard" />

go_advance.java

 findViewById(R.id.redirectLength).setOnClickListener(
              new View.OnClickListener() {
                  @Override
                  public void onClick(View view) {
                      Intent i=new Intent(go_advance.this,advance_mix.class);
                      startActivity(i);
                  }
              }
      );

go_advance class contains the intent which starts the advance_mix activity, which further lays out the advance_length layout file.

The problem is when redirect_length button is clicked it shows me a white screen?

Why is it happening?