Fix parsing nullable parameters

samples/ControlGallery/ControlGallery/Views/NavigationSource.razor

@@ -13,6 +13,7 @@
             <Button Text="Navigate with float" OnClick="NavigateWithFloat"></Button>
             <Button Text="Navigate with decimal" OnClick="NavigateWithDecimal"></Button>
             <Button Text="Navigate with Guid" OnClick="NavigateWithGuid"></Button>
+            <Button Text="Navigate with Nullable<Guid>" OnClick="NavigateWithNullableGuid"></Button>
             <Button Text="Navigate with Bool" OnClick="NavigateWithBool"></Button>
         </StackLayout>
     </ScrollView>
@@ -29,5 +30,6 @@
     async Task NavigateWithFloat() => await NavigationManager.NavigateToAsync("/float/55.43");
     async Task NavigateWithDecimal() => await NavigationManager.NavigateToAsync("/decimal/55.43");
     async Task NavigateWithGuid() => await NavigationManager.NavigateToAsync($"/guid/{Guid.NewGuid()}");
+    async Task NavigateWithNullableGuid() => await NavigationManager.NavigateToAsync($"/nullable-guid/{Guid.NewGuid()}");
     async Task NavigateWithBool() => await NavigationManager.NavigateToAsync("/bool/true");
 }

samples/ControlGallery/ControlGallery/Views/NavigationTarget.razor

@@ -7,6 +7,7 @@
 @page "/float/{Float}"
 @page "/decimal/{Decimal}"
 @page "/guid/{Guid}"
+@page "/nullable-guid/{NullableGuid}"
 @page "/bool/{Bool}"
 
 <ContentPage>
@@ -23,6 +24,7 @@
         <Label Text="@($"Float = {Float}")"></Label>
         <Label Text="@($"Decimal = {Decimal}")"></Label>
         <Label Text="@($"Guid = {Guid}")"></Label>
+        <Label Text="@($"Guid? = {NullableGuid}")"></Label>
         <Label Text="@($"Bool = {Bool}")"></Label>
     </StackLayout>
 </ContentPage>
@@ -37,6 +39,7 @@
     [Parameter] public float Float { get; set; }
     [Parameter] public decimal Decimal { get; set; }
     [Parameter] public Guid Guid { get; set; }
+    [Parameter] public Guid? NullableGuid { get; set; }
     [Parameter] public bool Bool { get; set; }
 
 

src/Microsoft.MobileBlazorBindings.Core/NativeComponentRenderer.cs

@@ -199,6 +199,8 @@ namespace Microsoft.MobileBlazorBindings.Core
         {
             bool success;
 
+            type = Nullable.GetUnderlyingType(type) ?? type;
+
             if (type == typeof(string))
             {
                 result = s;