.Bottom is read-only - winforms

Question

I'm working on a PowerShell script that uses forms and panels that are docked. I was able to create the form and panels just fine, but I'm having issues getting a listbox to resize during runtime using $inputbox.Bottom = $form.Height - 215 to control the size, but I recieve the error
'Bottom' is a read-only property.
Simply using Fill in the panel will not work because I have buttons above and below the listbox. Here is a sample of my code:
[void] [System.Reflection.Assembly]::LoadWithPartialName(“System.Windows.Forms”)
[void] [System.Reflection.Assembly]::LoadWithPartialName(“System.Drawing”)
$form.ResizeEnd
$form = New-Object System.Windows.Forms.Form
$form.Size = New-Object System.Drawing.Size(1040,459)
$form.KeyPreview = $true
$form.StartPosition = ‘centerscreen’
$form.BackColor = 'MidnightBlue'
$form.Add_KeyDown({if($_.KeyCode -eq "Escape"){$form.Close()}})
$form.Text = "Dialog Box 2.0"
$form.Icon = [system.drawing.icon]::ExtractAssociatedIcon($PSHOME + "\powershell_ise.exe")
$buttonPanel3 = New-Object Windows.Forms.Panel
$buttonPanel3.Size = New-Object Drawing.Size #(290,70)
$buttonPanel3.Dock = "left"
$buttonPanel3.BackColor = 'Blue'
$inputbox = New-Object System.Windows.Forms.ListBox
$inputbox.BorderStyle = 'NONE'
$inputbox.Font = New-Object System.Drawing.Font(“segoe UI”,9)
$inputbox.SelectionMode = "MultiExtended"
$inputbox.Left = 10
$inputbox.Top = 105
$inputbox.Width = 200
$inputbox.Bottom = $form.Height -215
$inputbox.Height = $form.Height -215
$buttonPanel3.Controls.Add($inputbox)
$form.Controls.Add($buttonPanel3)
$form.ShowDialog()
If someone could give some sample code of a listbox that resizes (mainly concerned with vertical expansion) when you resize the form that would be excellent.

Answer 1

I ended up completely rearranging my form and using the fill method, but I wanted to put in a tidbit about form resizing since that was the true issue here.
The resize handler for the form would be $form.Add_Resize({}). Inside the brackets I could modify the height and width properties as desired. In this case, I only wanted the height property, so the code would be like:
[void] [System.Reflection.Assembly]::LoadWithPartialName(“System.Windows.Forms”)
[void] [System.Reflection.Assembly]::LoadWithPartialName(“System.Drawing”)
$form.ResizeEnd
$form = New-Object System.Windows.Forms.Form
$form.Size = New-Object System.Drawing.Size(1040,459)
$form.KeyPreview = $true
$form.StartPosition = ‘centerscreen’
$form.BackColor = 'MidnightBlue'
$form.Add_KeyDown({if($_.KeyCode -eq "Escape"){$form.Close()}})
$form.Text = "Dialog Box 2.0"
$form.Icon = [system.drawing.icon]::ExtractAssociatedIcon($PSHOME + "\powershell_ise.exe")
$form.Add_Resize({
$inputbox.Height = $form.Height -215
})
$buttonPanel3 = New-Object Windows.Forms.Panel
$buttonPanel3.Size = New-Object Drawing.Size #(290,70)
$buttonPanel3.Dock = "left"
$buttonPanel3.BackColor = 'Blue'
$inputbox = New-Object System.Windows.Forms.ListBox
$inputbox.BorderStyle = 'NONE'
$inputbox.Font = New-Object System.Drawing.Font(“segoe UI”,9)
$inputbox.SelectionMode = "MultiExtended"
$inputbox.Left = 10
$inputbox.Top = 105
$inputbox.Width = 200
$inputbox.Height = $form.Height -215
$buttonPanel3.Controls.Add($inputbox)
$form.Controls.Add($buttonPanel3)
$form.ShowDialog()