仮想ディスプレイをソフトで再現！ダミーアダプタのエミュレーター「Virtual Display Driver」の設定手順

# 画面解像度を変更するPowerShellスクリプト

# C#コード
Add-Type -TypeDefinition @"
using System;
using System.Runtime.InteropServices;

public class ScreenResolution
{
    [StructLayout(LayoutKind.Sequential)]
    public struct DEVMODE
    {
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
        public string dmDeviceName;
        public short  dmSpecVersion;
        public short  dmDriverVersion;
        public short  dmSize;
        public short  dmDriverExtra;
        public int    dmFields;
        public int    dmPositionX;
        public int    dmPositionY;
        public int    dmDisplayOrientation;
        public int    dmDisplayFixedOutput;
        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 int    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;
    }

    [DllImport("user32.dll")]
    public static extern int EnumDisplaySettings(string deviceName, int modeNum, ref DEVMODE devMode);

    [DllImport("user32.dll")]
    public static extern int ChangeDisplaySettings(ref DEVMODE devMode, int flags);

    public const int ENUM_CURRENT_SETTINGS = -1;
    public const int CDS_UPDATEREGISTRY = 0x01;
    public const int DISP_CHANGE_SUCCESSFUL = 0;

    public static bool SetResolution(int width, int height)
    {
        DEVMODE dm = new DEVMODE();
        dm.dmSize = (short)Marshal.SizeOf(typeof(DEVMODE));
        if (0 != EnumDisplaySettings(null, ENUM_CURRENT_SETTINGS, ref dm))
        {
            dm.dmPelsWidth = width;
            dm.dmPelsHeight = height;

            int iRet = ChangeDisplaySettings(ref dm, CDS_UPDATEREGISTRY);
            return iRet == DISP_CHANGE_SUCCESSFUL;
        }
        return false;
    }
}
"@

# 解像度を設定
$width = 1920
$height = 1080

# 変更実行
if ([ScreenResolution]::SetResolution($width, $height)) {
    Write-Output "解像度を${width}x${height}に変更しました。"
} else {
    Write-Output "解像度の変更に失敗しました。"
}