How to show the text of the selected checkbox in a Toast?

I have tried this:

public void onCheckboxClicked(View view) {
    // La view è checked?
    boolean checked = ((CheckBox) view).isChecked();
    // Seleziona quale casella di controllo selezionare
    switch (view.getId()) {
        case R.id.checkBox:
            if (checked)
                Toast.makeText( getApplicationContext(), "Hai selezionato: " + checkBox.getText(), Toast.LENGTH_SHORT ).show();}

But I get this error:

java.lang.IllegalStateException: Could not execute method for android:onClick

The OnClick method is missing, but how can I use it together with the onCheckboxClicked method? Sorry I'm a beginner. Thanks