Expose GetFileHash & VerifyFileHash for .NET Core

[iainnicol]

These tasks already exist in Microsoft.Build.Tasks.Core.dll, but were
not exposed with a <UsingTask>. I presume this is an oversight. In
contrast, these tasks are already exposed from
Microsoft.Build.Tasks.v4.0, with a <UsingTask>.

[rainersigwald]

Great catch! Those tasks are new (added in #3398) and not exposed from the v4.0, so only the new lines you're adding make sense.

Can you please delete the existing lines as part of this PR as well?

[iainnicol]

Yes, I like the bleeding edge :).

Thanks for the explanation. I had assumed that .NET Framework MSBuild uses Microsoft.Build.Tasks.v4.0.dll, and .NET Core MSBuild uses Microsoft.Build.Tasks.Core.dll. But I now see that MSBuild, for both Framework and Core, ships Microsoft.Build.Tasks.Core.dll. Also, Microsoft.Build.Tasks.v4.0.dll is shipped separately, in the .NET Framework. Yeah?

Existing lines deleted.

[rainersigwald]

Thanks!

[japj]

ah, this explains why I couldn't use these tasks in VS2017 15.8. When will this be shipped (and does it include an update xsd by any chance)?

[rainersigwald]

@japj The fix will be in 16.0 (it should be in Preview 2 released last week).

As a workaround for older versions, you can include explicit UsingTasks before your usage of the task. If you include a condition on $(MSBuildVersion) you can keep it compatible with fixed MSBuilds.

    <UsingTask TaskName="Microsoft.Build.Tasks.GetFileHash"                           AssemblyName="Microsoft.Build.Tasks.Core, Version=15.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" Condition="'$(MSBuildVersion)' < '16.0.360'" />
    <UsingTask TaskName="Microsoft.Build.Tasks.VerifyFileHash"                        AssemblyName="Microsoft.Build.Tasks.Core, Version=15.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" Condition="''$(MSBuildVersion)' < '16.0.360'" />

<Target Name="Whatever">
 <GetFileHash ... />
</Target>

and does it include an update xsd by any chance

It does not, but should. Filed #4103.

[japj]

@rainersigwald great! Thanks for the info and updating the documentation!

[hickford]

@rainersigwald After fixing some typos, the workaround worked for me:

<UsingTask TaskName="Microsoft.Build.Tasks.GetFileHash" AssemblyName="Microsoft.Build.Tasks.Core, Version=15.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" Condition="'$(MSBuildVersion)' &lt; '16.0.360'" />
<UsingTask TaskName="Microsoft.Build.Tasks.VerifyFileHash" AssemblyName="Microsoft.Build.Tasks.Core, Version=15.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" Condition="'$(MSBuildVersion)' &lt; '16.0.360'" />