Switch statement produces incorrect result - winforms

Question

I'm creating a script for our support department and interns. I have a working script but wanted to use a GUI to it a bit easier for our interns. At this moment I'm pulling my hair out right now, I've copied the function below and and would like to have the value of $task1_exec. But when I try to put the return $Result in a variable the $Task1 variable is printed not the $Task1_exec one.
$FormTitle = "Formtitle"
$ScriptPath = $(get-location).Path;
$task1 = "Task 1"
$task1_exec = "Perform task 1"
$task2 = "Task 2"
$task2_exec = "Perform task 2"
$task3 = "Task 3"
$task3_exec = "Perform task 3"
$task4 = "Task 4"
$task4_exec = "Perform task 4"
function Prompt-SelectionList
{
Param(
[Parameter(Position=0,Mandatory=$true)][string]$Description,
[Parameter(Position=1,Mandatory=$true)][string[]]$List
)
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Drawing")
$Form = New-Object System.Windows.Forms.Form
$Form.Text = $FormTitle
$Form.Size = New-Object System.Drawing.Size(500,450) #(300,200)
$Form.StartPosition = "CenterScreen"
$btnOK = New-Object System.Windows.Forms.Button
$btnOK.Location = New-Object System.Drawing.Size(125,375)
$btnOK.Size = New-Object System.Drawing.Size(125,25)
$btnOK.Text = "Run..."
$Form.Controls.Add($btnOK)
$btnCancel = New-Object System.Windows.Forms.Button
$btnCancel.Location = New-Object System.Drawing.Size(250,375)
$btnCancel.Size = New-Object System.Drawing.Size(125,25)
$btnCancel.Text = "Exit"
$btnCancel.Add_Click({ $script:Result = $null; $Form.Close() })
$Form.Controls.Add($btnCancel)
$Label = New-Object System.Windows.Forms.Label
$Label.Location = New-Object System.Drawing.Size(10,20)
$Label.Size = New-Object System.Drawing.Size(480,20)
$Label.Text = $Description
$Form.Controls.Add($Label)
$ListBox = New-Object System.Windows.Forms.ListBox
$ListBox.Location = New-Object System.Drawing.Size(10,40)
$ListBox.Size = New-Object System.Drawing.Size(460,330)
$List | ForEach-Object { [void] $ListBox.Items.Add($_) }
$Form.Controls.Add($ListBox)
$Form.KeyPreview = $True
$Form.Add_KeyDown({ if ($_.KeyCode -eq "Enter") { $script:Result = $ListBox.SelectedItem; $Form.Close() }})
$Form.Add_KeyDown({ if ($_.KeyCode -eq "Escape") { $script:Result = $null; $Form.Close() }})
$btnOK.Add_Click({ $script:Result = $ListBox.SelectedItem; $Form.Close() })
$Form.Topmost = $True
$Form.Add_Shown({ $Form.Activate() })
[void] $Form.ShowDialog()
return $Result
}
function Do-PromptTask
{
switch -wildcard (Prompt-SelectionList "Chose task to run:" #($task1,$task2,$task3,$task4))
{
$task1{$task1_exec}
$task2{$task2_exec}
$Task3{$task3_exec}
$Task4{$task4_exec}
""{Exit} #End Selection (cancel selected)
# "*"{Do-PromptTask} #Keep prompting until "cancel" selected
}
}
Do-PromptTask
My wish is that I could return $task1_exec to a variable so when Do-PromptTask is finished the return can be used to call another script
. ".\Bin\$Result.ps1"

Answer 1

It looks like you're on the right track.
Let's pretend I run Do-PromptTask, chose Task 1, and click Run...
The $result variable from Prompt-SelectionList is passed back to the Switch statement and is out of scope at this point. The switch is doing its job and matching the conditional which then prints $task1_exec, but $result is of no use at this point. If you want to store $task1_exec as a variable, you'd need to set something equal to it. However, I will say you could just act on it in the switch statement without storing it in a variable, if that makes sense.
Less code approach...
function Do-PromptTask
{
switch -wildcard (Prompt-SelectionList "Chose task to run:" #($task1,$task2,$task3,$task4))
{
$task1{Invoke-Expression $task1_exec}
$task2{Invoke-Expression $task2_exec}
$Task3{Invoke-Expression $task3_exec}
$Task4{Invoke-Expression $task4_exec}
""{Exit} #End Selection (cancel selected)
# "*"{Do-PromptTask} #Keep prompting until "cancel" selected
}
}
If you're set on storing the variable, you could do something like this...
function Do-PromptTask
{
switch -wildcard (Prompt-SelectionList "Chose task to run:" #($task1,$task2,$task3,$task4))
{
$task1{$task_result = $task1_exec}
$task2{$task_result = $task2_exec}
$Task3{$task_result = $task3_exec}
$Task4{$task_result = $task4_exec}
""{Exit} #End Selection (cancel selected)
# "*"{Do-PromptTask} #Keep prompting until "cancel" selected
}
Invoke-Expression $task_result
}