Combobox Itemsource throws Exception when setting to a single item collection

Question

When setting the ItemSource of a WPF Combobox to a DataRowCollection programmatically from Powershell with just one entry, I'm getting this error message:

Ausnahme beim Festlegen von "ItemsSource": "Der Wert "System.Data.DataRow" vom Typ "System.Data.DataRow" kann nicht in den Typ "System.Collections.IEnumerable" konvertiert werden.

which roughly translates to:

Exception on setting of "ItemsSource": The value "System.Data.DataRow" of type "System.Data.DataRow" cannot be converted to type "System.Collections.IEnumerable

If my query results in a DataRowCollection with two or more entries, the setter ItemSource of the ComboBox just works fine. The function is written in Powershell and I already tried to cast the DataRowCollection to an array to make a workaround for this exception.

What should I deliver to the ItemSource setter, if the DataRowCollection has just one entry?

Many thanks in advance for your help.

Edit Here is some code as requested:

$connection = new-object system.data.SqlClient.SQLConnection($connectionString)
$command = new-object system.data.sqlclient.sqlcommand($sqlCommand,$connection)
$connection.Open()

$adapter = New-Object System.Data.sqlclient.sqlDataAdapter $command
$dataset = New-Object System.Data.DataSet
$adapter.Fill($dataSet) | Out-Null

$connection.Close()

$rows = $dataSet.Tables[0].Rows #i am querying only one table
#$combobox is the combobox element of the wpf window
$combobox.ItemSource = $rows #If $rows has just one element, this is the point where the exception occurs

Answer 1

I found a little workaround. Now i am casting the single DataRow item to an array and adding an empty string. Without adding an empty string, the same exception occurs.

$rows = $dataSet.Tables[0].Rows
#simple hack, to ensure this method always returns an array. 
#if just one element is in Rows, wpf complains about a single datarow not being an enumerable
if($rows.Count -eq 1) 
{ 
    $rows = @($rows,"")
} 

Now the setter ItemSource accepts the $rows , but of course, the empty string will be shown in the ComboBox .