Set Viewpager height inside Scrollview in android

Wrap your pager row inside CustomScrollView instead of wrapping the pager inside CustomScrollview. And Don’t fix height of Viewpager as Piyush Gupath commented. Use wrapcontent.

To fix the height of the viewpager we can customize the viewpager class.

public class WrapContentViewPager extends ViewPager {

private int mCurrentPagePosition = 0;

public WrapContentViewPager(Context context) {
    super(context);
}

public WrapContentViewPager(Context context, AttributeSet attrs) {
    super(context, attrs);
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    try {
        View child = getChildAt(mCurrentPagePosition);
        if (child != null) {
            child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
            int h = child.getMeasuredHeight();
            heightMeasureSpec = MeasureSpec.makeMeasureSpec(h, MeasureSpec.EXACTLY);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}

public void reMeasureCurrentPage(int position) {
    mCurrentPagePosition = position;
    requestLayout();
}
}

where this reMeasureCurrentPage should be called at viewpager onPageSelected callback.and CustomScrollView is the parent view.

mViewPager = new ViewPager(mContext) {
        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);

            View view = getChildAt(this.getCurrentItem());
            if (view != null) {
                view.measure(widthMeasureSpec, heightMeasureSpec);
            }
            setMeasuredDimension(getMeasuredWidth(), measureHeight(heightMeasureSpec, view));
        }

        private int measureHeight(int measureSpec, View view) {
            int result = 0;
            int specMode = MeasureSpec.getMode(measureSpec);
            int specSize = MeasureSpec.getSize(measureSpec);

            if (specMode == MeasureSpec.EXACTLY) {
                result = specSize;
            } else {
                // set the height from the base view if available
                if (view != null) {
                    result = view.getMeasuredHeight();
                }
                if (specMode == MeasureSpec.AT_MOST) {
                    result = Math.min(result, specSize);
                }
            }
            return result;
        }
    };

Try this way

<com.xxx.myapp.android.ui.CustomScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="center"
    android:fadingEdge="none"
    android:fillViewport="true"
    android:gravity="center">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:descendantFocusability="blocksDescendants"
        android:orientation="vertical" >

        <android.support.v4.view.ViewPager
            android:id="@+id/viewPager"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_gravity="top"
            android:layout_marginTop="10dp" />  
    </LinearLayout>
</com.xxx.myapp.android.ui.CustomScrollView> 

This is the best and easy solution :

1) Inside your custom ViewPager Class –

override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
    var heightMeasureSpec = heightMeasureSpec
    val mode = MeasureSpec.getMode(heightMeasureSpec)
    // Unspecified means that the ViewPager is in a ScrollView WRAP_CONTENT.
    // At Most means that the ViewPager is not in a ScrollView WRAP_CONTENT.
    if (mode == MeasureSpec.UNSPECIFIED || mode == MeasureSpec.AT_MOST) {
        // super has to be called in the beginning so the child views can be initialized.
        super.onMeasure(widthMeasureSpec, heightMeasureSpec)
        var height = 0
        for (i in 0 until childCount) {
            val child = getChildAt(i)
            child.measure(
                widthMeasureSpec,
                MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED)
            )
            val h = child.measuredHeight
            if (h > height) height = h
        }
        heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY)
    }
    // super has to be called again so the new specs are treated as exact measurements
    super.onMeasure(widthMeasureSpec, heightMeasureSpec)
}

2) While Setting the adapter to your ViewPager –

val viewPagerAdapter = ViewPagerAdapter(fragmentList, supportFragmentManager)
view_pager.adapter = viewPagerAdapter
view_pager.measure(LinearLayout.LayoutParams.MATCH_PARENT,LinearLayout.LayoutParams.WRAP_CONTENT)`
view_pager.currentItem = 0