Change loading indicator Offset in Xamarin.Forms RefreshView - xamarin.forms

Question

On Xamarin.Forms (iOS Android), I need to change the loading-indicator position on the RefreshView. I need to add offset, so the indicator is visible if you have a bar overlapping the ScrollView-RefreshView combo and trigger pullOnRefresh.
Loading-indicator in the top edge
EDIT: thanks to Junior Jiang - MSFT- Android solution
I also implement a solution for xamarin.iOS
[assembly: ExportRenderer(typeof(RefreshView), typeof(CustomRefreshViewRenderer))]
namespace CustomRefresh.iOS {
public class CustomRefreshViewRenderer : RefreshViewRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<RefreshView> e)
{
base.OnElementChanged(e);
foreach (var nativeView in Subviews)
updateRefreshSettings(nativeView);
}
void updateRefreshSettings(UIView view) {
if (view is UIScrollView)
{
var scrollView = view as UIScrollView;
if (scrollView.RefreshControl != null)
{
var bounds = scrollView.RefreshControl.Bounds;
scrollView.RefreshControl.Bounds = new CGRect(bounds.X, -(100), bounds.Width, bounds.Height);
}
}
//add more scrollable view types
}
}
}

Answer 1

You can custom a RefreshViewRenderer to achieve that .
In Android , there is a MOriginalOffsetTop to modify the offset of loading indicator . In addition , also can use SetProgressViewOffset to set the start and end position of indicator .
Code as follow :
using Android.Content;
using RefreshViewDemo.Droid;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;
[assembly: ExportRenderer(typeof(RefreshView), typeof(CustomRefreshViewRenderer))]
namespace RefreshViewDemo.Droid
{
public class CustomRefreshViewRenderer : RefreshViewRenderer
{
public CustomRefreshViewRenderer(Context context) : base(context)
{
MOriginalOffsetTop = 100;
// SetProgressViewOffset(true, 100, 101);
}
}
}
In iOS , the loading indicator belong to UIRefreshControl of UIScrollView , there is no direct way to change it's offset . Unless override all content view in Renderer then can achieve that . You can refer this Xamarin.Forms/Xamarin.Forms.Platform.iOS/Renderers/RefreshViewRenderer.cs to know what the RefreshView is made of .
====================Update=====================
Shared code is based on this official sample :https://learn.microsoft.com/en-us/samples/xamarin/xamarin-forms-samples/userinterface-refreshviewdemo/
For Android , just need to create a CustomRefreshViewRenderer class in android solution .
The effect of SetProgressViewOffset(true, 100, 101) , it seems like the indicator not moving :