Directory.build.targets

<Project>
  <PropertyGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
    <DefineConstants>$(DefineConstants);PORTABLE;NETSTANDARD_20</DefineConstants>
  </PropertyGroup>
  <PropertyGroup Condition="'$(TargetFramework)' == 'net46'">
    <DefineConstants>$(DefineConstants);NET_46;XAML</DefineConstants>
  </PropertyGroup>
  <PropertyGroup Condition="'$(TargetFramework)' == 'uap10.0'">
    <DefineConstants>$(DefineConstants);NETFX_CORE;XAML;WINDOWS_UWP</DefineConstants>
    <TargetPlatformVersion>10.0.14393.0</TargetPlatformVersion>
  </PropertyGroup>
  <PropertyGroup Condition="'$(TargetFramework)' == 'Xamarin.iOS10'">
    <DefineConstants>$(DefineConstants);MONO;UIKIT;COCOA</DefineConstants>
  </PropertyGroup>
   <PropertyGroup Condition="'$(TargetFramework)' == 'Xamarin.Mac20'">
    <DefineConstants>$(DefineConstants);MONO;COCOA</DefineConstants>
  </PropertyGroup>
  <PropertyGroup Condition="'$(TargetFramework)' == 'Xamarin.tvOS10'">
    <DefineConstants>$(DefineConstants);MONO;UIKIT;COCOA</DefineConstants>
  </PropertyGroup>
  <PropertyGroup Condition="'$(TargetFramework)' == 'MonoAndroid70'">
    <DefineConstants>$(DefineConstants);MONO;ANDROID</DefineConstants>
  </PropertyGroup>

  <ItemGroup Condition=" '$(TargetFramework)' == 'uap10.0' ">
    <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform " Version="5.2.2" />
  </ItemGroup>
</Project>