dotnet/maui · error · InvalidOperationException

Implement INativeElementView on cell renderer: {ContentCell.

Error message

Implement INativeElementView on cell renderer: {ContentCell.GetType().AssemblyQualifiedName}

What it means

ContextActionCell.Element getter boxes ContentCell as INativeElementView and throws InvalidOperationException if it is not. The cell context-actions feature relies on the underlying cell renderer implementing INativeElementView so that the Xamarin Element can be retrieved; if the registered cell renderer type lacks that interface, context actions cannot function and the contract is broken.

Source

Thrown at src/Compatibility/Core/src/iOS/ContextActionCell.cs:77

		public bool IsOpen
		{
			get { return ScrollDelegate.IsOpen; }
		}

		ContextScrollViewDelegate ScrollDelegate
		{
			get { return (ContextScrollViewDelegate)_scroller.Delegate; }
		}

		Element INativeElementView.Element
		{
			get
			{
				var boxedCell = ContentCell as INativeElementView;
				if (boxedCell == null)
				{
					throw new InvalidOperationException($"Implement {nameof(INativeElementView)} on cell renderer: {ContentCell.GetType().AssemblyQualifiedName}");
				}

				return boxedCell.Element;
			}
		}

		public void Close()
		{
			if (_scroller == null)
				return;

			_scroller.ContentOffset = new PointF(0, 0);
		}

		public override void LayoutSubviews()
		{
			base.LayoutSubviews();

View on GitHub (pinned to f377ff1c5e)

Solutions

Implement INativeElementView on the custom cell renderer (provide the Element property).
Verify the renderer type reported in the message; register or fix the correct renderer.
Avoid using ContextActions on cells whose renderers are not under your control.

Example fix

// before
public class MyCell : UITableViewCell { /* no INativeElementView */ }
// after
public class MyCell : UITableViewCell, INativeElementView
{
    public Element Element { get; set; }
}

Defensive patterns

Strategy: type-guard

Validate before calling

if (!(ContentCell is INativeElementView))
    throw new InvalidOperationException($"Cell renderer {ContentCell.GetType()} must implement INativeElementView to use ContextActions.");

Type guard

static bool SupportsContextActions(UITableViewCell cell) => cell is INativeElementView;

Prevention

Implement INativeElementView on every custom cell renderer.
Verify the registered renderer type before using ContextActions.
Prefer built-in cell renderers when possible.

When it happens

Trigger: Using ContextActions on a Cell whose registered iOS cell renderer does not implement INativeElementView; a custom Cell renderer registered without INativeElementView; a ViewCell renderer replacement from a third party.

Common situations: Registering a custom cell renderer via [assembly: ExportCell] that forgets to implement INativeElementView; upgrading a renderer package that drops the interface; mixing ViewCell with custom renderers that bypass the default.

Related errors

AI-assisted analysis of dotnet/maui@f377ff1c5e (2026-08-13). Data as JSON: /api/errors/926c803254ab7bc5. Report an issue: GitHub.