.NET Core locking files

This may also help when running your aspnetcore app in IIS.

Add the following to your csproj:

  <Target Name="PreBuild" BeforeTargets="PreBuildEvent">
    <Exec Command="echo &quot;App Offline&quot; /a &gt; &quot;$(ProjectDir)app_offline.htm&quot;" />
  </Target>

  <Target Name="PostBuild" AfterTargets="PostBuildEvent">
    <Exec Command="del &quot;$(ProjectDir)app_offline.htm&quot;" />
  </Target>