Bring Powershell-Console to front from WinForms - windows

Question

im trying to bring my powershell console to front, even if it is minimized.
I found following code:
function Show-Process($Process, [Switch]$Maximize)
{
$sig = '
[DllImport("user32.dll")] public static extern bool ShowWindowAsync(IntPtr hWnd, int nCmdShow);
[DllImport("user32.dll")] public static extern int SetForegroundWindow(IntPtr hwnd);
'
if ($Maximize) { $Mode = 3 } else { $Mode = 4 }
$type = Add-Type -MemberDefinition $sig -Name WindowAPI -PassThru
$hwnd = $process.MainWindowHandle
$null = $type::ShowWindowAsync($hwnd, $Mode)
$null = $type::SetForegroundWindow($hwnd)
}
Show-Process -Process (Get-Process -Id $pid)
It works fine, but when i call the function from a Button Click event, the console wont show.
What is the Problem? Is there a way to bring the powershell Console to front when using a WinForms GUI?
Here is the example GUI Code:
function Show-Process($Process, [Switch]$Maximize)
{
$sig = '
[DllImport("user32.dll")] public static extern bool ShowWindowAsync(IntPtr hWnd, int nCmdShow);
[DllImport("user32.dll")] public static extern int SetForegroundWindow(IntPtr hwnd);
'
if ($Maximize) { $Mode = 3 } else { $Mode = 4 }
$type = Add-Type -MemberDefinition $sig -Name WindowAPI -PassThru
$hwnd = $process.MainWindowHandle
$null = $type::ShowWindowAsync($hwnd, $Mode)
$null = $type::SetForegroundWindow($hwnd)
}
Add-Type -AssemblyName System.Windows.Forms
[System.Windows.Forms.Application]::EnableVisualStyles()
$Form = New-Object system.Windows.Forms.Form
$Form.ClientSize = '446,266'
$Form.text = "Form"
$Form.TopMost = $false
$Button1 = New-Object system.Windows.Forms.Button
$Button1.text = "button"
$Button1.width = 60
$Button1.height = 30
$Button1.location = New-Object System.Drawing.Point(75,29)
$Button1.Font = 'Microsoft Sans Serif,10'
$Button1.Add_Click({
Show-Process -Process (Get-Process -Id $pid)
})
$Form.controls.AddRange(#($Button1))
[void]$Form.ShowDialog()

Answer 1

Thanks to #iRon's answer, i was able to figure it out, how i want it.
For anyone curious, the problem is, you only can get the consoles MainwindowHandle as long as ShowDialog wasn't called.
So i save the console Handle in a variable and i use the Form_Shown event to get the Form WindowHandle, since Form_Load still returns the Console Handle.
$sig = '
[DllImport("user32.dll")] public static extern bool ShowWindowAsync(IntPtr hWnd, int nCmdShow);
[DllImport("user32.dll")] public static extern int SetForegroundWindow(IntPtr hwnd);'
$type = Add-Type -MemberDefinition $sig -Name WindowAPI -PassThru
[IntPtr]$handleConsole = (Get-Process -Id $pid).MainWindowHandle
[void]$type::ShowWindowAsync($handleConsole, 4);[void]$type::SetForegroundWindow($handleConsole)
Add-Type -AssemblyName System.Windows.Forms
[System.Windows.Forms.Application]::EnableVisualStyles()
$Form = New-Object system.Windows.Forms.Form
$Form.ClientSize = '446,266'
$Form.text = "Form"
$Form.TopMost = $false
$Form.Add_Shown({
$global:handleForm = (Get-Process -Id $pid).MainWindowHandle
})
$Button1 = New-Object system.Windows.Forms.Button
$Button1.text = "Clone ad-USer"
$Button1.width = 60
$Button1.height = 30
$Button1.location = New-Object System.Drawing.Point(75,29)
$Button1.Font = 'Microsoft Sans Serif,10'
$Button1.Add_Click({
[void]$type::ShowWindowAsync($handleConsole, 4);[void]$type::SetForegroundWindow($handleConsole)
Read-Host -Prompt "Please Enter a Value"
[void]$type::ShowWindowAsync($global:handleForm, 4);[void]$type::SetForegroundWindow($global:handleForm)
})
$Form.controls.AddRange(#($Button1))
[void]$Form.ShowDialog()
Now, if i press the Button, to console pops up in front.
After the User enter something into the Console, the Form comes to front again.

Answer 2

Unfortunately, I can't completely fix it, but maybe others might help you further based on my findings:
First of all, the process within the button click event is a different process space as where the parent PowerShell host runs in. This can be easily proven but revealing the $hwhd with Write-Host $hwnd in the Show-Process function and also calling the Show-Process function prior calling the ShowDialog:
Show-Process -Process (Get-Process -Id $pid)
[void]$Form.ShowDialog()
In other words: to fix this part, you will need to the catch the parent $Pid from the PowerShell window first:
$Button1.Add_Click({
Show-Process -Process $MyProcess
})
$Form.controls.AddRange(#($Button1))
$MyProcess = Get-Process -Id $pid
Show-Process -Process $MyProcess
[void]$Form.ShowDialog()
The above snippet works, but as soon I remove (or comment out) the line Show-Process -Process $MyProcess (at the host level), it breaks again...

Answer 3

As you've discovered, .MainWindowHandle is not a static property (from the linked docs; emphasis added):
The main window is the window opened by the process that currently has the focus [...]
Therefore, what the value of the current process' .MainWindowHandle property changes from the console-window handle to the WinForms window while the form is being displayed.[1]
Caching the console-window handle before you display the form is definitely an option, but there's an easier way, given that you're already using Add-Member with WinAPI P/Invoke declarations: The GetConsoleWindow() WinAPI function always returns the current process' console-window handle.
Additionally, your $Forms form instance has a .Handle property, which directly returns the form's window handle - no (Get-Process -Id $pid).MainWindowHandle call needed.
The following solution therefore needs no global or script-level variables and confines querying the window handles to the button-click event handler:
# P/Invoke signatures - note the addition of GetConsoleWindow():
$sig = '
[DllImport("user32.dll")] public static extern bool ShowWindowAsync(IntPtr hWnd, int nCmdShow);
[DllImport("user32.dll")] public static extern int SetForegroundWindow(IntPtr hwnd);
[DllImport("kernel32.dll")] public static extern IntPtr GetConsoleWindow();'
$type = Add-Type -MemberDefinition $sig -Name WindowAPI -PassThru
Add-Type -AssemblyName System.Windows.Forms
$Form = New-Object system.Windows.Forms.Form -Property #{
ClientSize = '446,266'
text = "Form"
}
$Button1 = New-Object system.Windows.Forms.Button -Property #{
text = "Test"
location = New-Object System.Drawing.Point(75, 29)
}
$Button1.Add_Click({
# Get this form's window handle.
$handleForm = $Form.Handle # More generically: $this.FindForm().Handle
# Get the console window's handle.
$handleConsole = $type::GetConsoleWindow()
# Activate the console window and prompt the user.
$null = $type::ShowWindowAsync($handleConsole, 4); $null = $type::SetForegroundWindow($handleConsole)
Read-Host -Prompt "Please Enter a Value"
# Reactivate this form.
$null = $type::ShowWindowAsync($handleForm, 4); $null = $type::SetForegroundWindow($handleForm)
})
$Form.controls.AddRange(#($Button1))
$null = $Form.ShowDialog()
[1] Note that a cached process object doesn't dynamically update its .MainWindowHandle value; you have to call .Refresh() manually.
Because iRon's solution caches the current-process object before displaying the form, it still happens to reflect the console-window handle inside the button-click handler.