apewer-dotnet/Apewer/Apewer.csproj

<Project Sdk="Microsoft.NET.Sdk">

	<Import Project="..\Apewer.props" />

	<PropertyGroup>
		<TargetFrameworks>netstandard2.1;netstandard2.0;netcoreapp3.1;net461;net40;net20</TargetFrameworks>
	</PropertyGroup>

	<!-- .NET Standard 2.1 -->
	<PropertyGroup Condition="'$(TargetFramework)'=='netstandard2.1'">
		<DefineConstants>NETSTD;HAVE_ASYNC;HAVE_BIG_INTEGER;$(DefineConstants);$(AdditionalConstants)</DefineConstants>
	</PropertyGroup>

	<!-- .NET Standard 2.0 -->
	<PropertyGroup Condition="'$(TargetFramework)'=='netstandard2.0'">
		<DefineConstants>NETSTD;HAVE_ASYNC;HAVE_BIG_INTEGER;$(DefineConstants);$(AdditionalConstants)</DefineConstants>
	</PropertyGroup>

	<!-- .NET Framework 2.0 -->
	<PropertyGroup Condition="'$(TargetFramework)'=='net20'">
		<DefineConstants>NETFX;NET20;$(DefineConstants);$(AdditionalConstants)</DefineConstants>
	</PropertyGroup>

	<!-- .NET Framework 4.0 -->
	<PropertyGroup Condition="'$(TargetFramework)'=='net40'">
		<DefineConstants>NETFX;NET40;HAVE_BIG_INTEGER;$(DefineConstants);$(AdditionalConstants)</DefineConstants>
	</PropertyGroup>

	<!-- .NET Framework 4.6.1 -->
	<PropertyGroup Condition="'$(TargetFramework)'=='net461'">
		<DefineConstants>NETFX;NET461;NET45;HAVE_ASYNC;HAVE_BIG_INTEGER;$(DefineConstants);$(AdditionalConstants)</DefineConstants>
	</PropertyGroup>

	<!-- .NET Core 3.1 -->
	<PropertyGroup Condition="'$(TargetFramework)'=='netcoreapp3.1'">
		<DefineConstants>HAVE_ASYNC;HAVE_BIG_INTEGER;$(DefineConstants);$(AdditionalConstants)</DefineConstants>
	</PropertyGroup>

</Project>