test

WindowsFormsApp1/Class1.cs

@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace WindowsFormsApp1
+{
+    class Class1
+    {
+    }
+}

WindowsFormsApp1/WindowsFormsApp1.csproj

@@ -46,6 +46,7 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Class1.cs" />
     <Compile Include="Form1.cs">
       <SubType>Form</SubType>
     </Compile>