Obtain file sizes in MSBuild script - msbuild

Question

Can I find out the sizes of a set of files from an MSBuild script without writing my own code?
MSBuild itself some metadata on individual items (for example, the last modified time at %(ModifiedTime)
), but no sizes. I can't see anything at http://msbuildextensionpack.com/.
Edit: based on Seva's answer, here's an inline task that returns the total size of an array of items:
<UsingTask TaskName="GetFileSize" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v4.0.dll">
<ParameterGroup>
<Files ParameterType="Microsoft.Build.Framework.ITaskItem[]" Required="true" />
<TotalSize ParameterType="System.Int64" Output="true"/>
</ParameterGroup>
<Task>
<Using Namespace="System.IO"/>
<Code Type="Fragment" Language="cs"><![CDATA[
long l = 0;
foreach (var item in Files) {
var fi = new FileInfo(item.ItemSpec);
l += fi.Length;
}
TotalSize = l;
]]></Code>
</Task>
</UsingTask>

Answer 1

You can actually use a sub-set of .Net API within msbuild projects using inline tasks.
E.g. the following prints out a file size of a single file:
<UsingTask TaskName="GetFileSize" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v4.0.dll">
<ParameterGroup>
<FileName Required="true" />
<FileSize ParameterType="System.Int64" Output="true"/>
</ParameterGroup>
<Task>
<Using Namespace="System.IO"/>
<Code Type="Fragment" Language="cs"><![CDATA[
FileInfo fi = new FileInfo(FileName);
FileSize = fi.Length;
]]></Code>
</Task>
</UsingTask>
<Target Name="PrintFileSize" >
<GetFileSize FileName="$(MyFileName)">
<Output TaskParameter="FileSize" PropertyName="MyFileSize" />
</GetFileSize>
<Message Text="file size of $(MyFileName) is $(MyFileSize)" />
</Target>