How to iterate through an array of objects in Powershell - powershell

Question

I'm doing some basic validation on form fields. What's the correct way to iterate through an array of objects to validate them? When I try the below I get
The property 'BackColor' cannot be found on this object. Verify that the property exists and can be set.
I guess what I'm missing is a way of telling Powershell these are references to other variables, rather than variables themselves.
$MandatoryFields = #(
'txtUsername',
'txtFirst',
'txtLast',
'txtEmail',
'ComboLicense'
)
ForEach ($Field in $MandatoryFields) {
If ([string]::IsNullOrWhitespace($Field.text)) {
$Validation = "failed"
$Field.BackColor = "red"
}
}
EDIT: Okay, what I needed was the actual variables in the array, like so:
$MandatoryFields = #(
$txtUsername,
$txtFirst,
$txtLast,
$txtEmail,
$ComboLicense
)

Answer 1

Try adding your objects to an array like below
$objects = [System.Collections.ArrayList]#()
$myObject = [PSCustomObject]#{
Name = 'Kevin'
Language = 'PowerShell'
State = 'Texas'
}
$objects.add($myObject)
$myObject1= [PSCustomObject]#{
Name = 'Kevin'
Language = 'PowerShell'
State = 'Texas'
}
$objects.add($myObject1)
foreach($obj in $objects){
$obj.firstname
}

Answer 2

I'm assuming your using System.Windows.Forms to create your form. If that's the case when adding controls you should assign a name to the control. Then you can loop through your controls and check if the control name matches your list of mandatory controls and then execute your check.
$MandatoryFields = #(
'txtUsername',
'txtFirst',
'txtLast',
'txtEmail',
'ComboLicense'
)
$Controls = MyForm.controls
ForEach ($c in $Controls) {
ForEach ($Field in $MandatoryFields) {
if ($c.Name -eq $Field) {
If ([string]::IsNullOrWhitespace($c.text)) {
$Validation = "failed"
$c.BackColor = "red"
}
}
}
}