Show a message box in PS1

messagebox.ps1

$script = @"
using System;
using System.Runtime.InteropServices;

public partial class MessageBoxer
{
    // Import user32.dll (containing the function we need) and define
    // the method corresponding to the native function.
    [DllImport(`"user32.dll`", SetLastError = true)]
    private static extern int MessageBox(IntPtr hWnd, string lpText, string lpCaption, uint uType);

    public static void ShowBox()
    {
        // Invoke the function as a regular managed method.
        MessageBox(IntPtr.Zero, `"Command-line message box`", `"Attention!`", 0);
    }
}
"@;

# Compile the C# code locally
Add-Type -TypeDefinition $script -Language CSharp

$args = @()
[MessageBoxer]::ShowBox()