NullPointerException: Attempt to invoke virtual method

Question

Attempt to invoke virtual method: void android.widget.Button.setTag(java.lang.Object)
on a null object reference.

error when I use androiddataBinding on Button like:

<Button
    android:id="@+id/btn_login"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginLeft="20dp"
    android:layout_marginRight="20dp"
    android:layout_marginTop="50dp"
    android:background="@{userInfo.isEmpty?@drawable/shape_gray_corner:@color/colorWhite}"
    android:text="@string/text_login"
    android:onClick="onViewClik"
    android:textColor="@color/colorWhite"
    android:textSize="@dimen/textsize_24" />

Answer 1

I think you have to try default color instead of drawable or use drawable at both places.

like this

android:background="@{userInfo.isEmpty ? @color/colorYellow : @color/colorWhite}"