MvvmCross: Cannot add more than one UIPickerView - xamarin.ios

Question

I'm building an iOS view using Xamarin and MvvmCross and I have come across an interesting little issue. I can't seem to add more than one UIPickerView to a UIView.
Add one view and all works well. Add a second and the simulator just hangs when I try and open the page.
This seems to be related to a UITextField with an InputView as I also have an issue if I try to add a UIDatePicker as well.
Nothing strange in the debug output.
Here is the code:
[Register("EditJobViewJobView")]
public class EditJobView : MvxViewController
{
public new EditJobViewModel ViewModel
{
get { return (EditJobViewModel)base.ViewModel; }
}
private const float _leftMargin = 6;
private const float _labelHeight = 20;
private const float _pickerHeight = 28;
private readonly UIFont _labelFont = UIFont.BoldSystemFontOfSize(18f);
private readonly UIFont _controlFont = UIFont.SystemFontOfSize(18f);
private readonly UIView _paddingInsert = new UIView(new RectangleF(0, 0, 4, 0));
private int _currentTop = 0;
public override void ViewDidLoad()
{
base.ViewDidLoad();
View = new UIView() { BackgroundColor = UIColor.White };
NavigationItem.SetRightBarButtonItem(new UIBarButtonItem("Save", UIBarButtonItemStyle.Bordered,
(sender, args) => ViewModel.OkCommand.Execute(null)), true);
// ios7 layout
if (RespondsToSelector(new Selector("edgesForExtendedLayout")))
EdgesForExtendedLayout = UIRectEdge.None;
Title = "Edit Job";
AddLabel("Job Status");
MvxPickerViewModel jobStatusPickerViewModel;
var jobStatusTextView = AddPickerView(out jobStatusPickerViewModel);
AddLabel("Job Priority");
MvxPickerViewModel jobPriorityPickerViewModel;
var jobPriorityTextView = AddPickerView(out jobPriorityPickerViewModel);
var set = this.CreateBindingSet<EditJobView, EditJobViewModel>();
set.Bind(jobStatusPickerViewModel).For(p => p.SelectedItem).To(vm => vm.SelectedJobStatusType);
set.Bind(jobStatusPickerViewModel).For(p => p.ItemsSource).To(vm => vm.JobStatusTypes);
set.Bind(jobStatusTextView).To(vm => vm.SelectedJobStatusType);
set.Bind(jobPriorityPickerViewModel).For(p => p.SelectedItem).To(vm => vm.SelectedJobPriority);
set.Bind(jobPriorityPickerViewModel).For(p => p.ItemsSource).To(vm => vm.JobPriorities);
set.Bind(jobPriorityTextView).To(vm => vm.SelectedJobPriority);
set.Apply();
}
private void AddLabel(string caption)
{
_currentTop += 10;
var frame = new RectangleF(_leftMargin, _currentTop, 300, _labelHeight);
var label = new UILabel(frame);
label.Font = _labelFont;
label.Text = caption;
AddView(label);
_currentTop += 2;
}
private UITextField AddPickerView(out MvxPickerViewModel pickerViewModel)
{
var textField = AddTextField();
var pickerView = new UIPickerView();
pickerViewModel = new MvxPickerViewModel(pickerView);
pickerView.Model = pickerViewModel;
pickerView.ShowSelectionIndicator = true;
textField.InputView = pickerView;
return textField;
}
private UITextField AddTextField()
{
var frame = new RectangleF(_leftMargin, _currentTop, 300, _pickerHeight);
var textField = new UITextField(frame);
textField.Layer.BorderColor = UIColor.Black.CGColor;
textField.Layer.BorderWidth = 1f;
textField.Font = _controlFont;
textField.LeftView = _paddingInsert;
textField.LeftViewMode = UITextFieldViewMode.Always;
AddView(textField);
return textField;
}
private void AddView(UIView view)
{
View.AddSubview(view);
_currentTop += (int)view.Frame.Height;
}
}
Any ideas?

Answer 1

This was caused by creating a shared padding insert across a number of UITextFields.
To fix this I changed
textField.LeftView = _paddingInsert;
to
textField.LeftView = new UIView(new RectangleF(0, 0, 4, 0));