Powershell resultset not being picked up in C#

To get an possible PowerShell error I would try sth. like this:

private void button1_Click(object sender, EventArgs e)        {            //If the logPath exists, delete the file            string logPath = "Output.Log";            if (File.Exists(logPath)) {                File.Delete(logPath);            }            string[] Servers = richTextBox1.Text.Split('\n');            //Pass each server name from the listview to the 'Server' variable            foreach (string Server in Servers) {                //PowerShell Script                string PSScript = @"            param([Parameter(Mandatory = $true, ValueFromPipeline = $true)][string] $server)            Set-ExecutionPolicy -Scope CurrentUser -ExecutionPolicy RemoteSigned -Force;            Import-Module SQLServer;            Try             {                Set-Location SQLServer:\\SQL\\$server -ErrorAction Stop;                 Get-ChildItem | Select-Object -ExpandProperty Name;            }             Catch             {                echo 'No SQL Server Instances';             }            ";                using (PowerShell psInstance = PowerShell.Create()) {                                                   psInstance.AddScript(PSScript);                    psInstance.AddParameter("server", Server);                    Collection<PSObject> results = psInstance.Invoke();                    if (psInstance.Streams.Error.Count > 0) {                        foreach (var errorRecord in psInstance.Streams.Error) {                            MessageBox.Show(errorRecord.ToString());                        }                    }                                   foreach (PSObject result in results) {                        File.AppendAllText(logPath, result + Environment.NewLine);                        // listBox1.Items.Add(result);                    }                               }            }        }

The reason it isn't working is that psInstance.AddParameter only adds parameters to commands, it doesn't work with a script. You'll need to find another way of getting the $server parameter into the script. Try these two powershell examples to see what I mean. The first will output all processes (ignores the AddParameter) while the second only shows svchost processes.

1)

$ps = [system.management.automation.powershell]::create()$ps.AddScript("get-process")$ps.AddParameter("name","svchost")$ps.invoke()

2)

$ps = [system.management.automation.powershell]::create()$ps.AddCommand("get-process")$ps.AddParameter("name","svchost")$ps.invoke()

I managed to get round this issue by using the Win32_service instead of SQLPS.

Param([Parameter(Mandatory = $true, ValueFromPipeline = $true)][string] $server)$localInstances = @()[array]$captions = GWMI Win32_Service -ComputerName $server | ?{$_.Name -match 'mssql *' -and $_.PathName -match 'sqlservr.exe'} | %{$_.Caption}ForEach($caption in $captions){   if ($caption -eq 'MSSQLSERVER')    {       $localInstances += 'MSSQLSERVER'   }   else    {       $temp = $caption | %{$_.split(' ')[-1]} | %{$_.trimStart('(')} | %{$_.trimEnd(')')}       $localInstances += ""$server\$temp""   }}$localInstances;