xamarin.android.StickyHeader 1.1.0

StickyHeader

A very simple library that allows you to stick any View as a header of a:

• ListView
• RecyclerView
• ScrollView

Adding a Sticky Header

To stick a header to a list view, we just need a ListView and any View to use as the header:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/layout_container">
    <ListView
        android:id="@+id/listview"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
    <FrameLayout
        android:id="@+id/header"
        android:layout_width="match_parent"
        android:layout_height="@dimen/max_height_header"
        android:background="@android:color/holo_blue_dark">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal|bottom"
            android:layout_marginBottom="10dp"
            android:text="Hello World!"
            android:textSize="25dp" />
    </FrameLayout>
</FrameLayout>

Once we have the layout inflated, we can use the StickyHeaderBuilder to attach the header to the list:

var listView = container.FindViewById<ListView>(Resource.Id.listview);
StickyHeaderBuilder
    .StickTo(listView)
    .SetHeader(Resource.Id.header, container)
    .SetMinHeight(250)
    .Apply();

Using a Sticky Header Animator

There are various animations that can be used when transitioning the header. This is easily done with the AnimatorBuilder type. Some of the built in transitions are:

• Scale
• Translation
• Fade
• Parallax

For simple transitions, we can pass a delegate that returns an AnimatorBuilder to the SetAnimator method:

.SetAnimator(() => {
    var image = View.FindViewById(Resource.Id.header_image);
    return AnimatorBuilder
      .Create()
      .ApplyVerticalParallax(image);
})

If we need more complex transitions, we can inherit from HeaderStickyAnimator:

public class IconActionBarAnimator : HeaderStickyAnimator
{
	private readonly View homeActionBar;
	private readonly int layoutResource;

	public IconActionBarAnimator(Activity activity, int layoutResource)
	{
		this.layoutResource = layoutResource;
		this.homeActionBar = activity.FindViewById(Android.Resource.Id.Home);
	}

	public override AnimatorBuilder CreateAnimatorBuilder()
	{
		var view = Header.FindViewById(layoutResource);
		var rect = new RectangleF(
			homeActionBar.Left, homeActionBar.Top,
			homeActionBar.Right, homeActionBar.Bottom);
		var point = new PointF(homeActionBar.Left, homeActionBar.Top);
		return AnimatorBuilder
			.Create()
			.ApplyScale(view, rect)
			.ApplyTranslation(view, point);
	}
}