Compress a folder using NTFS compression in .NET

Question

I want to compress a folder using NTFS compression in .NET. I found this post, but it does not work. It throws an exception (\"Invalid Parameter\").

DirectoryI         


        

Answer 1

This is a slight adaption of Igal Serban answer. I ran into a subtle issue with the Name having to be in a very specific format. So I added some Replace("\\", @"\\").TrimEnd('\\') magic to normalize the path first, I also cleaned up the code a bit.

var dir = new DirectoryInfo(_outputFolder);

if (!dir.Exists)
{
    dir.Create();
}

if ((dir.Attributes & FileAttributes.Compressed) == 0)
{
    try
    {
        // Enable compression for the output folder
        // (this will save a ton of disk space)

        string objPath = "Win32_Directory.Name=" + "'" + dir.FullName.Replace("\\", @"\\").TrimEnd('\\') + "'";

        using (ManagementObject obj = new ManagementObject(objPath))
        {
            using (obj.InvokeMethod("Compress", null, null))
            {
                // I don't really care about the return value, 
                // if we enabled it great but it can also be done manually
                // if really needed
            }
        }
    }
    catch (Exception ex)
    {
        System.Diagnostics.Trace.WriteLine("Cannot enable compression for folder '" + dir.FullName + "': " + ex.Message, "WMI");
    }
}