Question

I have this C# code to enumerate controls of a Form instance:

private void button1_Click(object sender, EventArgs e)
{
    textBox1.Text = "";

    Form2 form2 = new Form2();

    foreach (Control control in form2.Controls)
    {
        PropertyDescriptorCollection properties = 
            TypeDescriptor.GetProperties(control);

        foreach (PropertyDescriptor property in properties)
        {
            textBox1.Text += (property.Name + Environment.NewLine);
        }
    }
}

This lists all controls names of a Form form2 in a TextBox. This is my attempt to reproduce this code in PowerShell:

$form = New-Object System.Windows.Forms.Form

foreach($control in $form.Controls)
{
    $properties = 
        [System.ComponentModel.TypeDescriptor]::GetProperties($control)

    foreach($property in $properties)
    {
        $property.Name
    } 
}

But this doesn’t work. $form.Control seems to come up empty so the foreach loop is never entered. How can i make the above C# code work in PowerShell?

[edit 1]

The above code obviously has a form with no controls on it. Here is updated PowerShell code with a form that has a Button added to its Controls collection, but with (seemingly) the same result of not enumerating the Controls collection:

$form = New-Object System.Windows.Forms.Form
$button = New-Object System.Windows.Forms.Button
$form.Controls.Add($Button)

$form.Controls.Count

foreach($control in $form.Controls)
{
    $properties = 
        [System.ComponentModel.TypeDescriptor]::GetProperties($control)

    foreach($property in $properties)
    {
        $property.DisplayName
    } 
}

[edit 2]

if i check the $property type:

foreach($property in $properties)
{
    $property.GetType().FullName
} 

GetType() returns:

System.ComponentModel.PropertyDescriptorCollection

where I expected PropertyDescriptor.

Answer 1

You just need to manually .GetEnumerator() — I’m not sure why Powershell isn’t unrolling that correctly.

$form = New-Object System.Windows.Forms.Form
$button = New-Object System.Windows.Forms.Button
$form.Controls.Add($Button)

$form.Controls.Count

foreach($control in $form.Controls)
{
    $properties = 
        [System.ComponentModel.TypeDescriptor]::GetProperties($control)

    foreach($property in $properties.GetEnumerator())
    {
        $property.DisplayName
    } 
}