Why isn't cell resizing when content is taller than the EstimatedSize (sizeHint) - ios

Question

I ported a table view implementation from Swift with a variable height cell. But in my Xamarin/ReactiveUI implementation, the cell does not resize when the content grows (i.e. when an optional label is displayed). Please note that the cell does resize to fit in the native Swift implementation.
Most answers online focus on the setting of two properties on UITableView: RowHeight and EstimatedHeight as well as using AutoLayout. My row height is set to UITableView.AutomaticDimension and the EstimatedHeight is set to 44f. I am using autolayout constraints which I will show below. I am using the BindTo extensions in ReactiveTableViewSourceExtensions.
I also tried setting the Text property of the optional label right away to test the theory that setting the property up front would provoke a resize.
Here are the pertinent lines of code:
In a ReactiveViewController<T> ctor:
this.WhenActivated(disposables =>
{
//// ...
// This method automatically wires up the cell reuse key to be the nameof my cell class which is what I want.
this.WhenAnyValue(view => view._cells)
.BindTo<IImportedFileViewModel, ImportedFileCell>(TableView, 44f)
.DisposeWith(disposables);
//// ...
});
Below in ViewDidLoad:
//// ...
TableView = new UITableView
{
RowHeight = UITableView.AutomaticDimension,
EstimatedRowHeight = 44f, // Setting or not setting this doesn't matter
SeparatorStyle = UITableViewCellSeparatorStyle.None,
AllowsSelection = false,
TranslatesAutoresizingMaskIntoConstraints = false,
};
//// ...
In the cell implementation:
ClipsToBounds = true;
PreservesSuperviewLayoutMargins = true;
ContentView.ClipsToBounds = true;
ContentView.PreservesSuperviewLayoutMargins = true;
var stackView = new UIStackView
{
TranslatesAutoresizingMaskIntoConstraints = false,
Axis = UILayoutConstraintAxis.Vertical,
Distribution = UIStackViewDistribution.Fill,
Alignment = UIStackViewAlignment.Fill,
Spacing = 4,
};
var fileStackView = new UIStackView
{
TranslatesAutoresizingMaskIntoConstraints = false,
Axis = UILayoutConstraintAxis.Horizontal,
Distribution = UIStackViewDistribution.Fill,
Alignment = UIStackViewAlignment.Top,
};
FilenameLabel = new UILabel
{
TranslatesAutoresizingMaskIntoConstraints = false,
Font = UIFont.SystemFontOfSize(15f, UIFontWeight.Medium),
};
fileStackView.AddArrangedSubview(FilenameLabel);
StatusImage = new UIImageView()
{
TranslatesAutoresizingMaskIntoConstraints = false,
ContentMode = UIViewContentMode.Center,
};
fileStackView.AddArrangedSubview(StatusImage);
stackView.AddArrangedSubview(fileStackView);
var reasonStackView = new UIStackView
{
TranslatesAutoresizingMaskIntoConstraints = false,
Axis = UILayoutConstraintAxis.Horizontal,
Distribution = UIStackViewDistribution.Fill,
Alignment = UIStackViewAlignment.Top,
};
// This is the optional label that, when its Text property is set, should resize the cell.
FailureReasonLabel = new UILabel
{
TranslatesAutoresizingMaskIntoConstraints = false,
Font = UIFont.SystemFontOfSize(13f, UIFontWeight.Medium),
Lines = 0,
};
reasonStackView.AddArrangedSubview(FailureReasonLabel);
stackView.AddArrangedSubview(reasonStackView);
ContentView.AddSubview(stackView);
stackView.BottomAnchor.ConstraintEqualTo(ContentView.LayoutMarginsGuide.BottomAnchor).Active = true;
stackView.TopAnchor.ConstraintEqualTo(ContentView.LayoutMarginsGuide.TopAnchor).Active = true;
stackView.LeadingAnchor.ConstraintEqualTo(ContentView.LayoutMarginsGuide.LeadingAnchor).Active = true;
stackView.TrailingAnchor.ConstraintEqualTo(ContentView.LayoutMarginsGuide.TrailingAnchor).Active = true;
StatusImage.HeightAnchor.ConstraintEqualTo(16f).Active = true;
StatusImage.WidthAnchor.ConstraintEqualTo(16f).Active = true;
I would be happy to get a solution to the problem using the basic structure I have now but I would also accept an example of some other pattern that someone has used (based on ReactiveUI) to get this working. I would prefer that the solution not be based on old manual resizing patterns like in the pre-iOS 8 days or some sort of hack.

Answer 1

So two things had to be adjusted to fix my issue.
The sizeHint parameter in the ReactiveUI BindTo method does not behave like TableView.EstimatedRowHeight, which is what I was assuming. So I ended up setting it to the auto dimension constant like this:
.BindTo<IImportedFileViewModel, ImportedFileCell>(TableView, (float)UITableView.AutomaticDimension)
I was thinking that I could just update the properties of the view models within the IObservableCollection implementation that is passed in to the BindTo method but it wasn't until I started provoking changed events on the collection itself (the collection that the view is bound to) that the cells started resizing themselves. So since I am using DynamicData as part of ReactiveUI, that meant calling SourceCache.AddOrUpdate(updatedViewModel) whenever I knew that the FailureReasonLabel had been set.
I am also going to try and restore the ReactiveUI tag that was removed from this post because I believe it to be a relevant part of this question and its answer.