TFS: How to raise warning if no files exist

In my build script run by TFS2008 I'm trying to copy all files from folder A to folder B recursively I've managed to do it using task:

<ItemGroup>
    <MyFiles Include="$(SolutionRoot)\MyFiles\**" />
</ItemGroup>

<Target Name="CopyFiles">
      <Message Text="Copy Files" />
      <Copy SourceFiles="@(MyFiles)"
            DestinationFolder="$(DeploymentFolder)\SomeFolder\%(RecursiveDir)" />

</Target>

I would like to raise a warning via TFS when MyFiles is empty.

So I have two questions:

1. How do I raise an warning via TFS?

2. How do I discover if the ItemGroup contains no files?

   开发者_Python百科

1) Warning Task

http://msdn.microsoft.com/en-us/library/92775st5.aspx

2) Use the Msbuildhelpder.ItemCount

http://www.msbuildextensionpack.com/help/4.0.2.0/index.html

And here is an example build file that demonstrates its use:

<Project ToolsVersion="4.0" DefaultTargets="Default;UpdateMetadata" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <PropertyGroup>
        <TPath>$(MSBuildProjectDirectory)\..\MSBuild.ExtensionPack.tasks</TPath>
        <TPath Condition="Exists('$(MSBuildProjectDirectory)\..\..\Common\MSBuild.ExtensionPack.tasks')">$(MSBuildProjectDirectory)\..\..\Common\MSBuild.ExtensionPack.tasks</TPath>
    </PropertyGroup>
    <Import Project="$(TPath)"/>

    <ItemGroup>
       <MyFiles Include="$(SolutionRoot)\MyFiles\**" />
    </ItemGroup>

    <Target Name="Default">
           <MSBuild.ExtensionPack.Framework.MsBuildHelper 
               TaskAction="GetItemCount" 
               InputItems1="@(MyFiles)">
              <Output TaskParameter="ItemCount" PropertyName="MyCount"/>
           </MSBuild.ExtensionPack.Framework.MsBuildHelper>
           <Warning
            Text=" No files in MyFiles collection."
            Condition="'$(MyCount)' &gt; '0'" />
    </Target>
</Project>