Update projects to target .NET 5

Author: augustoproiete

global.json

@@ -1,7 +1,7 @@
 {
   "sdk": {
     "allowPrerelease": false,
-    "version": "3.1.100",
+    "version": "5.0.100",
     "rollForward": "latestFeature"
   }
 }

sample/Ookii.Dialogs.Wpf.Sample/Ookii.Dialogs.Wpf.Sample.csproj

@@ -1,8 +1,9 @@
 <Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
 
   <PropertyGroup>
-    <TargetFrameworks>net45;netcoreapp3.1</TargetFrameworks>
+    <TargetFrameworks>net45;netcoreapp3.1;net5.0-windows</TargetFrameworks>
     <OutputType>WinExe</OutputType>
+    <SupportedOSPlatform>windows7</SupportedOSPlatform>
     <UseWPF>true</UseWPF>
     <UseWindowsForms>true</UseWindowsForms>
     <RootNamespace>Ookii.Dialogs.Wpf.Sample</RootNamespace>

src/Ookii.Dialogs.Wpf/Ookii.Dialogs.Wpf.csproj

@@ -1,7 +1,8 @@
 <Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp3.1;net45</TargetFrameworks>
+    <TargetFrameworks>net5.0-windows;netcoreapp3.1;net45</TargetFrameworks>
+    <SupportedOSPlatform>windows7</SupportedOSPlatform>
     <UseWPF>true</UseWPF>
     <UseWindowsForms>true</UseWindowsForms>
     <RootNamespace>Ookii.Dialogs.Wpf</RootNamespace>
@@ -40,6 +41,10 @@
     <DefineConstants>$(DefineConstants);NETCORE31</DefineConstants>
   </PropertyGroup>
 
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'net5.0-windows' ">
+    <DefineConstants>$(DefineConstants);NET5</DefineConstants>
+  </PropertyGroup>
+
   <PropertyGroup>
     <MinClientVersion>3.3</MinClientVersion>
     <PackageId>Ookii.Dialogs.Wpf</PackageId>