WinUI: Changed the way to detect a WinUI application

Author: optsing

src/Directory.Build.props

@@ -14,7 +14,7 @@
   <PropertyGroup Condition="$(TargetFramework.StartsWith('uap'))">
     <DefineConstants>$(DefineConstants);UWP;WINDOWS_MODERN</DefineConstants>
   </PropertyGroup>
-  <PropertyGroup Condition="$(TargetFramework.StartsWith('net6.0-windows10'))">
+  <PropertyGroup Condition="$(UseWinUI) == true">
     <DefineConstants>$(DefineConstants);WINUI;WINDOWS_MODERN</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(TargetFramework)' == 'uap10.0'">

src/LibVLCSharp/LibVLCSharp.csproj

@@ -73,7 +73,7 @@ LibVLC needs to be installed separately, see VideoLAN.LibVLC.* packages.</Descri
     <PackageReference Include="Microsoft.Bcl.Async" Version="1.0.168" />
   </ItemGroup>
 
-  <ItemGroup Condition="$(TargetFramework.StartsWith('uap')) Or $(TargetFramework.StartsWith('net6.0-windows10')) ">
+  <ItemGroup Condition="$(TargetFramework.StartsWith('uap')) Or $(UseWinUI) == true">
     <Compile Include="Platforms\Windows\**\*.cs" />
     <PackageReference Include="SharpDX.Direct3D11" Version="4.2.0" />
     <Page Include="Themes\Generic.xaml">
@@ -82,7 +82,7 @@ LibVLC needs to be installed separately, see VideoLAN.LibVLC.* packages.</Descri
     </Page>
   </ItemGroup>
 
-  <ItemGroup Condition="$(TargetFramework.StartsWith('net6.0-windows10')) ">
+  <ItemGroup Condition="$(UseWinUI) == true">
     <PackageReference Include="Microsoft.WindowsAppSDK" Version="1.1.1" />
   </ItemGroup>
 
@@ -104,4 +104,4 @@ LibVLC needs to be installed separately, see VideoLAN.LibVLC.* packages.</Descri
       <BuildOutputInPackage Condition="$(TargetFramework.Contains('monoandroid'))" Include="$(OutputPath)LibVLCSharp.Android.AWindow.dll" />
     </ItemGroup>
   </Target>
-</Project>
+</Project>