NativeZip

  <UsingTask TaskName="NativeZip" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v4.0.dll">
    <ParameterGroup>
      <InputFileNames ParameterType="Microsoft.Build.Framework.ITaskItem[]" Required="true" />
      <OutputFileName ParameterType="System.String" Required="true" />
      <OverwriteExistingFile ParameterType="System.Boolean" Required="false" />
      <Flatten ParameterType="System.Boolean" Required="false" />
      <RemoveRoot ParameterType="System.String" Required="false" />
    </ParameterGroup>
    <Task>
      <Reference Include="System.IO.Compression" />
      <Using Namespace="System.IO.Compression" />
      <Code Type="Fragment" Language="cs">
      <![CDATA[
        var fileMode = OverwriteExistingFile ? FileMode.Create : FileMode.CreateNew;
        Directory.CreateDirectory(Path.GetDirectoryName(OutputFileName));
        using (var archive = new ZipArchive(new FileStream(OutputFileName, fileMode), ZipArchiveMode.Create))
        {
            foreach (var inputFileName in InputFileNames.Select(f => f.ItemSpec))
            {
                var archiveName = Flatten ? Path.GetFileName(inputFileName) : (String.IsNullOrEmpty(RemoveRoot) ? inputFileName : inputFileName.Replace(RemoveRoot, ""));
                var archiveEntry = archive.CreateEntry(archiveName);
                using (var fs = new FileStream(inputFileName, FileMode.Open))
                {
                    using (var zipStream = archiveEntry.Open())
                    {
                        fs.CopyTo(zipStream);
                    }
                }
            }
        }
      ]]>
      </Code>
    </Task>
  </UsingTask>