Use NullToCollapsedConverter instead property

Author: Ivan Grek

src/PackageManager.UI/Views/Browser.xaml

@@ -159,8 +159,8 @@
                                     </TextBlock>
 
                                     <!-- Published Date -->
-                                    <Label Grid.Row="3" Grid.Column="0" Content="Published Date:" Visibility="{Binding PublishedVisibility, Mode=OneWay}"/>
-                                    <TextBlock Grid.Row="3" Grid.Column="1" Text="{Binding Published, Mode=OneWay}" Visibility="{Binding PublishedVisibility, Mode=OneWay}" />
+                                    <Label Grid.Row="3" Grid.Column="0" Content="Published Date:" Visibility="{Binding Published, Converter={StaticResource NullToCollapsedConverter}}"/>
+                                    <TextBlock Grid.Row="3" Grid.Column="1" Text="{Binding Published, Mode=OneWay}" Visibility="{Binding Published, Converter={StaticResource NullToCollapsedConverter}}" />
 
                                     <!-- Project URL -->
                                     <Label Grid.Row="4" Grid.Column="0" Content="Project URL:" />

src/PackageManager/PackageManager.csproj

@@ -10,8 +10,4 @@
     <PackageReference Include="Neptuo.Observables" Version="2.0.0" />
   </ItemGroup>
 
-  <ItemGroup>
-    <Reference Include="PresentationCore" />
-  </ItemGroup>
-
 </Project>

src/PackageManager/ViewModels/PackageViewModel.cs

@@ -7,7 +7,6 @@
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
-using System.Windows;
 
 namespace PackageManager.ViewModels
 {
@@ -24,9 +23,6 @@ public class PackageViewModel : ObservableModel
         public string Description => model.Description;
         public string Authors => model.Authors;
         public DateTime? Published => model.Published;
-        public Visibility PublishedVisibility => Published is null
-            ? Visibility.Collapsed
-            : Visibility.Visible;
 
         public string Tags => model.Tags;
         public Uri IconUrl => model.IconUrl;