collection filling with nulls on second run

Question

I have the following method that runs a powershell command to get the ad user list and fill a collection

<

private void fillADUsers()
        {
            
            AdUsers = new Collection<PSObject>();
            AdUsers = PSCommandToRun("Get-ADUser -filter * -properties LastLogon, whenCreated, Enabled, LockedOut");
        }

After running this it fills a listview with the details. This works fine on the first run but when i run it again the LastLogon and whenCreated are giving me a null reference exception

why would the second run of the method give me nulls when it gives me the correct details the first time and how can i avoid this?

Answer 1

Hi ,

The best thing to do in these cases is to clear the PowerShell session state before running the command, this way we make sure we always get the latest information from Active Directory. Here are some changes to your script for you to try and see if it solves your problem:

private void fillADUsers()
{
    AdUsers = new Collection<PSObject>();
    
    using (PowerShell powershell = PowerShell.Create())
    {
        powershell.AddScript("Clear-Variable -Scope Global");
        powershell.AddScript("Clear-Variable -Scope Local");
        powershell.AddScript("Clear-Variable -Scope Script");
        
        powershell.AddScript("Get-ADUser -Filter * -Properties LastLogon, whenCreated, Enabled, LockedOut");
        
        try
        {
            AdUsers = powershell.Invoke();
        }
        catch (Exception ex)
        {
            Console.Error.WriteLine(ex);
        }
    }
}

Regards,