Program.cs

using System.IO;
using System.Net.NetworkInformation;
using System.Runtime.InteropServices;

namespace Planetoid_DB
{
	internal static class Program
	{
		private const int FEATURE_DISABLE_NAVIGATION_SOUNDS = 21;
		private const int SET_FEATURE_ON_THREAD = 0x00000001;
		private const int SET_FEATURE_ON_PROCESS = 0x00000002;
		private const int SET_FEATURE_IN_REGISTRY = 0x00000004;
		private const int SET_FEATURE_ON_THREAD_LOCALMACHINE = 0x00000008;
		private const int SET_FEATURE_ON_THREAD_INTRANET = 0x00000010;
		private const int SET_FEATURE_ON_THREAD_TRUSTED = 0x00000020;
		private const int SET_FEATURE_ON_THREAD_INTERNET = 0x00000040;
		private const int SET_FEATURE_ON_THREAD_RESTRICTED = 0x00000080;

		// Necessary dll import
		/// <summary>
		/// 
		/// </summary>
		/// <param name="FeatureEntry"></param>
		/// <param name="dwFlags"></param>
		/// <param name="fEnable"></param>
		/// <returns></returns>
		[DllImport(dllName: "urlmon.dll")]
		[PreserveSig]
		[return: MarshalAs(unmanagedType: UnmanagedType.Error)]
		private static extern int CoInternetSetFeatureEnabled(int FeatureEntry, [MarshalAs(unmanagedType: UnmanagedType.U4)] int dwFlags, bool fEnable);
		/// <summary>
		///  The main entry point for the application.
		/// </summary>
		[STAThread]
		static void Main()
		{
			CoInternetSetFeatureEnabled(FeatureEntry: FEATURE_DISABLE_NAVIGATION_SOUNDS, dwFlags: SET_FEATURE_ON_PROCESS, fEnable: true);
			ApplicationConfiguration.Initialize();

			if (!File.Exists(path: Properties.Resources.FilenameMpcorb))
			{
				if (MessageBox.Show(text: I10nStrings.MpcorbDatNotFoundText, caption: I10nStrings.MpcorbDatNotFoundCaption, buttons: MessageBoxButtons.YesNo, icon: MessageBoxIcon.Warning, defaultButton: MessageBoxDefaultButton.Button1) == DialogResult.Yes)
				{
					if (!NetworkInterface.GetIsNetworkAvailable())
					{
						MessageBox.Show(text: I10nStrings.NoInternetConnectionText, caption: I10nStrings.ErrorCaption, buttons: MessageBoxButtons.OK, icon: MessageBoxIcon.Error);
						Application.Exit();
					}
					else
					{
						using DownloadUpdateForm formDownloaderForMpcorbDat = new();
						if (formDownloaderForMpcorbDat.ShowDialog() == DialogResult.OK)
						{
							Application.Run(mainForm: new PlanetoidDBForm());
						}
						else
						{
							Application.Exit();
						}
					}
				}
				else
				{
					Application.Exit();
				}
			}
			else
			{
				Application.Run(mainForm: new PlanetoidDBForm());
			}
		}
	}
}