Clicking a textview to change fragment

Question

I am trying to build my first android app using Kotlin but I am stuck on a very simple situation. I am using Kotlin android extensions and I am getting a Null pointer exception.

<TextView
        android:id="@+id/tvGoToRegisterFrag"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/btn_sign_in"
        android:text="@string/haven_t_registered_yet"
        android:paddingTop="10dp"
        android:textColor="@color/colorAccent"
        android:layout_centerHorizontal="true"/>

With this I used

tvGoToRegisterFrag.setOnClickListener {
        goToRegister()
    }

I do know I can use

tvGoToRegisterFrag?.setOnClickListener {
        goToRegister()
    }

To get rid of crashing but still I am not sure why the object is null and does not do anything when clicked. All of this is done in a Fragment if that changes anything.

Answer 1

One reason you may be getting NPE is that you are using it in the wrong lifecycle method I was having a similar error when using it in onCreateView instead you should only use Kotlin android extensions in onViewCreated.