未調用MVVMCross iOS自定義可見性轉換器

Question

我有一個可見性轉換器，用於在Android上完美運行的列表，但是我無法在iOS中調用Convert方法。

public class ListVisibilityConverter : MvxBaseVisibilityValueConverter<IList>
{
    protected override MvxVisibility Convert(IList value, object parameter, CultureInfo culture)
    {
        var inverse = false;
        if (parameter != null)
        {
            inverse = (bool)parameter;
        }

        var listHasEntries = (value != null) && value.Count > 0;

        if (inverse)
        {
            return listHasEntries ? MvxVisibility.Collapsed : MvxVisibility.Visible;
        }
        else
        {
            return listHasEntries ? MvxVisibility.Visible : MvxVisibility.Collapsed;
        }
    }
}

我在ViewController的ViewDidLoad中的綁定中使用轉換器...

var set = this.CreateBindingSet<AddFriendsFromContactsViewController, AddFriendsFromContactsViewModel>();
set.Bind(collectionView).For("Visibility").To(vm => vm.SectionedCollection).WithConversion("ListVisibility", true);
set.Bind(noContactsFoundLabel).For("Visibility").To(vm => vm.SectionedCollection).WithConversion("ListVisibility", false);
set.Apply();

在Setup.cs中，我已確認使用以下代碼找到了轉換器...

protected override void InitializeLastChance()
{
    base.InitializeLastChance();
    var registry = Mvx.Resolve<IMvxValueConverterLookup>();
    var f = registry.Find(BindingStrings.ListVisibility);
    Mvx.Trace("Custom converter was found : {0}", f != null);
}

Answer 1

在iOS項目的設置中覆蓋ValueConverterAssemblies並手動添加值轉換器解決了該問題。

protected override IEnumerable<Assembly> ValueConverterAssemblies
{
    get
    {
        var assemblies = base.ValueConverterAssemblies;
        var valueConverterAssemblies = assemblies as Assembly[] ?? assemblies.ToArray();
        valueConverterAssemblies.ToList().Add(typeof(ListVisibilityConverter).Assembly);
        return valueConverterAssemblies;
    }
}