Set-ScreenResolution Pre-check using PowerShell®

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One might think why would you require to change resolution using a script, let alone why do it with PowerShell

  1. PowerShell is native to Windows, a windows guy's first love to perform admin jobs
  2. When you are working with OCR / Image recognition based workloads, screen resolution plays a pivotal role

I come from RPA background, where in end goal is to automate back-office jobs mostly repetitive / rule-based in nature

Yeah those clerical jobs that suck big time 😵😵😵, hence there is where RPA comes to rescue

Coming back to our problem, lets break it into small parts,

  1. We need to know the desired screen resolution, lets say I want it to be 1920 * 1080

  2. We need to query the system to know current primary monitor resolution, lets say it is set to 1024 * 768

  3. Change current resolution to desired resolution, if not already 😁

Enough said, lets try to achieve this via code,

If you would have used Power Shell before, you would know that there is no inbuilt cmdlet available to change the screen resolution. So we will make use of a Set-ScreenResolution function available on the PSGallery

So our problem part 3 is resolved, now we need to query system to know the current resolution which we can do by using WMIObject in PS as below,

$SVerticalReso = Get-WmiObject -Class Win32_VideoController | Select-Object CurrentVerticalResolution
$SHorizontalReso = Get-WmiObject -Class Win32_VideoController | Select-Object CurrentHorizontalResolution

Final step is to change add all three steps together in logical sequence, which can be found in script below,

Function Set-ScreenResolution { 

<# 
    .Synopsis 
        Sets the Screen Resolution of the primary monitor 
    .Description 
        Uses Pinvoke and ChangeDisplaySettings Win32API to make the change 
    .Example 
        Set-ScreenResolution -Width 1024 -Height 768         
#> 

param ( 
[Parameter(Mandatory=$true, 
           Position = 0)] 
[int] 
$Width, 

[Parameter(Mandatory=$true, 
           Position = 1)] 
[int] 
$Height 
) 

$pinvokeCode = @" 

using System; 
using System.Runtime.InteropServices; 

namespace Resolution 
{ 

    [StructLayout(LayoutKind.Sequential)] 
    public struct DEVMODE1 
    { 
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)] 
        public string dmDeviceName; 
        public short dmSpecVersion; 
        public short dmDriverVersion; 
        public short dmSize; 
        public short dmDriverExtra; 
        public int dmFields; 

        public short dmOrientation; 
        public short dmPaperSize; 
        public short dmPaperLength; 
        public short dmPaperWidth; 

        public short dmScale; 
        public short dmCopies; 
        public short dmDefaultSource; 
        public short dmPrintQuality; 
        public short dmColor; 
        public short dmDuplex; 
        public short dmYResolution; 
        public short dmTTOption; 
        public short dmCollate; 
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)] 
        public string dmFormName; 
        public short dmLogPixels; 
        public short dmBitsPerPel; 
        public int dmPelsWidth; 
        public int dmPelsHeight; 

        public int dmDisplayFlags; 
        public int dmDisplayFrequency; 

        public int dmICMMethod; 
        public int dmICMIntent; 
        public int dmMediaType; 
        public int dmDitherType; 
        public int dmReserved1; 
        public int dmReserved2; 

        public int dmPanningWidth; 
        public int dmPanningHeight; 
    }; 



    class User_32 
    { 
        [DllImport("user32.dll")] 
        public static extern int EnumDisplaySettings(string deviceName, int modeNum, ref DEVMODE1 devMode); 
        [DllImport("user32.dll")] 
        public static extern int ChangeDisplaySettings(ref DEVMODE1 devMode, int flags); 

        public const int ENUM_CURRENT_SETTINGS = -1; 
        public const int CDS_UPDATEREGISTRY = 0x01; 
        public const int CDS_TEST = 0x02; 
        public const int DISP_CHANGE_SUCCESSFUL = 0; 
        public const int DISP_CHANGE_RESTART = 1; 
        public const int DISP_CHANGE_FAILED = -1; 
    } 



    public class PrmaryScreenResolution 
    { 
        static public string ChangeResolution(int width, int height) 
        { 

            DEVMODE1 dm = GetDevMode1(); 

            if (0 != User_32.EnumDisplaySettings(null, User_32.ENUM_CURRENT_SETTINGS, ref dm)) 
            { 

                dm.dmPelsWidth = width; 
                dm.dmPelsHeight = height; 

                int iRet = User_32.ChangeDisplaySettings(ref dm, User_32.CDS_TEST); 

                if (iRet == User_32.DISP_CHANGE_FAILED) 
                { 
                    return "Unable To Process Your Request. Sorry For This Inconvenience."; 
                } 
                else 
                { 
                    iRet = User_32.ChangeDisplaySettings(ref dm, User_32.CDS_UPDATEREGISTRY); 
                    switch (iRet) 
                    { 
                        case User_32.DISP_CHANGE_SUCCESSFUL: 
                            { 
                                return "Success"; 
                            } 
                        case User_32.DISP_CHANGE_RESTART: 
                            { 
                                return "You Need To Reboot For The Change To Happen.\n If You Feel Any Problem After Rebooting Your Machine\nThen Try To Change Resolution In Safe Mode."; 
                            } 
                        default: 
                            { 
                                return "Failed To Change The Resolution"; 
                            } 
                    } 

                } 


            } 
            else 
            { 
                return "Failed To Change The Resolution."; 

            } 
        } 

        private static DEVMODE1 GetDevMode1() 
        { 
            DEVMODE1 dm = new DEVMODE1(); 
            dm.dmDeviceName = new String(new char[32]); 
            dm.dmFormName = new String(new char[32]); 
            dm.dmSize = (short)Marshal.SizeOf(dm); 
            return dm; 
        } 
    } 
} 

"@ 

Add-Type $pinvokeCode -ErrorAction SilentlyContinue 
[Resolution.PrmaryScreenResolution]::ChangeResolution($width,$height) 

}

# Desired Screen resolution values
$RVerticalReso = "1920"
$RHorizontalReso = "1080"

# Mail receipients - Change it support team's email
$Recipients = supportteam@example.com

$SVerticalReso = Get-WmiObject -Class Win32_VideoController | Select-Object CurrentVerticalResolution
$SHorizontalReso = Get-WmiObject -Class Win32_VideoController | Select-Object CurrentHorizontalResolution

# Output current resolution values from WMIObject converted to String
$SVert = ($SVerticalReso.CurrentVerticalResolution | Out-String).Trim()
$SHori = ($SHorizontalReso.CurrentHorizontalResolution | Out-String).Trim()

#Comparison if Current Resolution = Desired Resolution??

if (($RVerticalReso -eq $SVert) -AND ($RHorizontalReso -eq $SHori))
    {
    $Timestamp = Get-Date -Format "dddd MM/dd/yyyy HH:mm"
    Write-Output "$TimeStamp $env:COMPUTERNAME Current Resolution is $SHori * $SVert and is correct as per the requirement"
    }
else
    {
    $ChangeReso = Set-ScreenResolution -Width $RVerticalReso -Height $RHorizontalReso 
    if ($ChangeReso -eq "Success")
        { 
          $Timestamp = Get-Date -Format "dddd MM/dd/yyyy HH:mm"
          Write-Output "$TimeStamp $env:COMPUTERNAME Current Resolution is $SHori * $SVert and is incorrect as per the requirement, changed to $RVerticalReso * $RHorizontalReso by the script" 
        }
    else
        {
          $Timestamp = Get-Date -Format "dddd MM/dd/yyyy HH:mm"
          Write-Output "$TimeStamp $env:COMPUTERNAME Current Resolution is $SHori * $SVert and is incorrect as per the requirement, required value is $RVerticalReso * $RHorizontalReso, script failed to change Resolution."

          # Send email to support team regarding the failure of Pre-check for as Resolution change didn't work
          $Outlook = New-Object -ComObject Outlook.Application
          $Mail = $Outlook.CreateItem(0)
          $Mail.To = "$Recipients"
          $Mail.Subject = "$TimeStamp $env:COMPUTERNAME Screen resolution change failed"
          $Mail.Body ="Current screen resolution for this computer is not correct, change it to desired value"
          $Mail.Send()
        }
    }

You can save this script as a .ps1 script and can trigger as below,

powershell -ExecutionPolicy ByPass -File "<your .ps1 file path>"

Using above script, you can change the resolution to desired value, and this step can act as a pre-check before running you OCR / Image based automation steps

To add a cherry on the top, I have added a mail sending snippet at end in case if script is failing to change resolution to notify you regarding the same (Outlook application should for this step)

Happy Automating!!! 👋👋

Do let me know below if this was useful to you!

Drop a like, if it was 😇

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