How can I do a screen capture in Windows PowerShell?

Question

How can I capture the screen in Windows PowerShell? I need to be able to save the screen to disk.

Answer 1

This PowerShell function will capture the screen in PowerShell and save it to an automatically numbered file. If the -OfWindow switch is used, then the current window will be captured.

This works by using the built in PRINTSCREEN / CTRL-PRINTSCREEEN tricks, and it uses a bitmap encoder to save the file to disk.

function Get-ScreenCapture
{
    param(    
    [Switch]$OfWindow        
    )


    begin {
        Add-Type -AssemblyName System.Drawing
        $jpegCodec = [Drawing.Imaging.ImageCodecInfo]::GetImageEncoders() | 
            Where-Object { $_.FormatDescription -eq "JPEG" }
    }
    process {
        Start-Sleep -Milliseconds 250
        if ($OfWindow) {            
            [Windows.Forms.Sendkeys]::SendWait("%{PrtSc}")        
        } else {
            [Windows.Forms.Sendkeys]::SendWait("{PrtSc}")        
        }
        Start-Sleep -Milliseconds 250
        $bitmap = [Windows.Forms.Clipboard]::GetImage()    
        $ep = New-Object Drawing.Imaging.EncoderParameters  
        $ep.Param[0] = New-Object Drawing.Imaging.EncoderParameter ([System.Drawing.Imaging.Encoder]::Quality, [long]100)  
        $screenCapturePathBase = "$pwd\ScreenCapture"
        $c = 0
        while (Test-Path "${screenCapturePathBase}${c}.jpg") {
            $c++
        }
        $bitmap.Save("${screenCapturePathBase}${c}.jpg", $jpegCodec, $ep)
    }
}

Hope this helps

Answer 2

You can also use .NET to take the screenshot programatically (which gives you finer control):

[Reflection.Assembly]::LoadWithPartialName("System.Drawing")
function screenshot([Drawing.Rectangle]$bounds, $path) {
   $bmp = New-Object Drawing.Bitmap $bounds.width, $bounds.height
   $graphics = [Drawing.Graphics]::FromImage($bmp)

   $graphics.CopyFromScreen($bounds.Location, [Drawing.Point]::Empty, $bounds.size)

   $bmp.Save($path)

   $graphics.Dispose()
   $bmp.Dispose()
}

$bounds = [Drawing.Rectangle]::FromLTRB(0, 0, 1000, 900)
screenshot $bounds "C:\screenshot.png"