fxc.exe /T fx_5_0 /Fo Basic.fxo Basic.fx

<ItemGroup>
  <CustomBuild Include="*.fx">
    <Message>Building shaders...</Message>
    <Command>fxc.exe /T fx_5_0 /Fo "$(OutDir)%(Filename).fxo" "%(Identity)"</Command>
    <Outputs>$(OutDir)%(Filename).fxo</Outputs>
  </CustomBuild>
</ItemGroup>