ChangeDisplaySettings in C# and Powershell, pass byte array as struct pointer

ChangeDisplaySettings.ps1

# Version 1. Unsafe C Style
$cp = [System.CodeDom.Compiler.CompilerParameters]::new()
$cp.CompilerOptions = '/unsafe'
$Display = Add-Type -TypeDefinition @'
using System;
using System.Runtime.InteropServices; 
public unsafe class Display 
{
  [DllImport("User32.dll")]
  public static extern bool EnumDisplaySettings(
    char* lpszDeviceName,
    int iModeNum,
    void* lpDevMode);

  [DllImport("User32.dll")]
  public static extern long ChangeDisplaySettings(
    void* lpDevMode,
    int flags);

  static void CopyInt32(Int32 v, byte[] arr, int offset)
  {
      byte* vp = (byte*)&v;
      for (int i = 0; i < sizeof(Int32); i++)
          arr[offset + i] = vp[i];
  }

  public static byte[] ChangeResolution(int bits, int width, int height, int refreshRate) 
  {
    byte[] dm = new byte[156];
    fixed (void* dmPtr = dm) 
    {
        Console.WriteLine(EnumDisplaySettings(null, -1, dmPtr));

        CopyInt32(0x5c0000, dm, 40);
        if (bits > 0)
            CopyInt32(bits, dm, 104);
        if (width > 0)
            CopyInt32(width, dm, 108);
        if (height > 0)
            CopyInt32(height, dm, 112);
        if (refreshRate > 0)
            CopyInt32(refreshRate, dm, 120);

        Console.WriteLine(ChangeDisplaySettings(dmPtr, 0));
    }

    return dm;
  }
}
'@ -Pas -CompilerParameters $cp

# Version 2 - byte array marshal
$Display = Add-Type -TypeDefinition @'
using System;
using System.Runtime.InteropServices; 
public class Display
{
  [DllImport("User32.dll")]
  public static extern bool EnumDisplaySettings(
    [param: MarshalAs(UnmanagedType.LPTStr)]
    string lpszDeviceName,
    [param: MarshalAs(UnmanagedType.U4)]
    int iModeNum,
    [param: MarshalAs(UnmanagedType.LPArray)]
    byte[] lpDevMode);

  [DllImport("User32.dll")]
  public static extern long ChangeDisplaySettings(
    [param: MarshalAs(UnmanagedType.LPArray)]
    byte[] lpDevMode,
    [param: MarshalAs(UnmanagedType.U4)]
    int flags);

  static void CopyInt32(Int32 v, byte[] arr, int offset)
  {
      byte[] vBytes = BitConverter.GetBytes(v);
      for (int i = 0; i < sizeof(Int32); i++)
          arr[offset + i] = vBytes[i];
  }

  public static byte[] ChangeResolution(int bits, int width, int height, int refreshRate) 
  {
    byte[] dm = new byte[156];
    Console.WriteLine(EnumDisplaySettings(null, -1, dm));

    CopyInt32(0x5c0000, dm, 40);
    if (bits > 0)
        CopyInt32(bits, dm, 104);
    if (width > 0)
        CopyInt32(width, dm, 108);
    if (height > 0)
        CopyInt32(height, dm, 112);
    if (refreshRate > 0)
        CopyInt32(refreshRate, dm, 120);

    Console.WriteLine(ChangeDisplaySettings(dm, 0));
    
    return dm;
  }
}
'@ -Pas

# Execute
#$Display::ChangeResolution(0, 1280, 720, 60)
$Display::ChangeResolution(32, 1920, 1080, 144)
#$Display::ChangeResolution(0, 0, 0, 144)
#$host.ui.RawUI.ReadKey("NoEcho,IncludeKeyDown")