How to get the scrollview total height = Scrollview.getScrollY() on Android

Question

I have already look on some forums but the tricks do not work for me.

I have this code:

scrollview = (ScrollView)v.findViewById(R.id.scrollView);
    scrollview.getViewTreeObserver().addOnScrollChangedListener(new OnScrollChangedListener() {

        @Override
        public void onScrollChanged() {

            Log.d(MainActivity.TAG, "scroll ch: "+scrollview.getScrollY()+"/"+scrollview.getChildAt(0).getHeight());
        }
    });

In my layout.xml

<ScrollView
    android:id="@+id/scrollView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true" >

    <LinearLayout
        android:id="@+id/principal"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:divider="@drawable/horiz"
        android:orientation="vertical"
        android:showDividers="end|middle" >
    </LinearLayout>
</ScrollView>

When I scroll down to the last I get the getScrollY() smaller than getChildAt(0).getHeight().

How can I get both having the same total size ?

Answer 1

Maybe change

layout_height="wrap_content"

to

layout_height="match_parent"