Generally, the most flexible option is to create a custom MSBuild task. This is all untested code meant to just to give you the idea:
In your msbuild file:
<UsingTask TaskName="FindFiles" AssemblyFile="FindFiles.dll" />
<!--
As you'll see below, SearchDirectory and SearchPatterns are input parameters,
MatchingFiles is an output parameter, SourceFiles is an ItemGroup assigned to
the output.
-->
<FindFiles SearchDirectory="$(MyDirectory)" SearchPatterns="*.dll;*.xml">
<Output ItemName="SourceFiles" TaskParameter="MatchingFiles" />
</FindFiles>
<!-- You can then use the generated ItemGroup output elsewhere. -->
<DocumentationSources>
<DocumentationSource sourceFile="@(SourceFiles)" xmlns="" />
</DocumentationSources>
FindFiles.cs:
using System;
using System.IO;
using System.Collections.Generic;
using Microsoft.Build.Framework;
using Microsoft.Build.Utilities;
namespace FindFiles
{
public class FindFiles : Task
{
// input parameter
[Required]
public string SearchDirectory { get; set; }
// output parameter
[Required]
public string[] SearchPatterns { get; set; }
[Output]
public string[] MatchingFiles { get; private set; }
private bool ValidateParameters()
{
if (String.IsNullOrEmpty(SearchDirectory))
{
return false;
}
if (!Directory.Exists(SearchDirectory))
{
return false;
}
if (SearchPatterns == null || SearchPatterns.Length == 0)
{
return false;
}
return true;
}
// MSBuild tasks use the command pattern, this is where the magic happens,
// refactor as needed
public override bool Execute()
{
if (!ValidateParameters())
{
return false;
}
List<string> matchingFiles = new List<string>();
try
{
foreach (string searchPattern in SearchPatterns)
{
matchingFiles.AddRange(
Directory.GetFiles(SearchDirectory, searchPattern)
);
}
}
catch (IOException)
{
// it might be smarter to just let this exception fly, depending on
// how you want the task to behave
return false;
}
MatchingFiles = matchingFiles.ToArray();
return true;
}
}
}