sbox-public/engine/Sandbox.Tools/Utility/FileAssociations.cs

using Microsoft.Win32;
using System;
using System.Runtime.InteropServices;

namespace Editor;

internal class FileAssociations
{
	/// <summary>
	/// Creates/updates file associations between .sbproj files and the editor
	/// </summary>
	internal static void Create()
	{
		var sboxExeFilePath = $"\"{FileSystem.Root.GetFullPath( "sbox-dev.exe" )}\"";

		try
		{
			RegistryKey fileTypeKey = Registry.CurrentUser.CreateSubKey( @"SOFTWARE\Classes\Sandbox.ProjectFile" );
			fileTypeKey.SetValue( "", "Sandbox Project File" );
			fileTypeKey.CreateSubKey( "DefaultIcon" ).SetValue( "", sboxExeFilePath );

			RegistryKey shellKey = fileTypeKey.CreateSubKey( "shell" );
			RegistryKey shellOpenKey = shellKey.CreateSubKey( "open" );
			shellOpenKey.SetValue( "", "Open" );
			shellOpenKey.CreateSubKey( "command" ).SetValue( "", sboxExeFilePath + " -project \"%1\"" );

			RegistryKey fileExtensionKey = Registry.CurrentUser.CreateSubKey( @"SOFTWARE\Classes\.sbproj" );
			fileExtensionKey.SetValue( "", "Sandbox.ProjectFile" );

			// Tell explorer the file association has been changed
			SHChangeNotify( 0x08000000, 0x0000, IntPtr.Zero, IntPtr.Zero );
		}
		catch ( Exception ex )
		{
			Log.Warning( ex, "Failed to associate project file extension" );
		}
	}

	[DllImport( "shell32.dll", CharSet = CharSet.Auto, SetLastError = true )]
	public static extern void SHChangeNotify( uint wEventId, uint uFlags, IntPtr dwItem1, IntPtr dwItem2 );
}