TBMM/GCMM/MainForm.cs

using GCMM.Properties;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace GCMM
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            modlist.Items.Clear();
            UpdateButton(installbtn, false);
            modinfobox.Text = "";
            if (string.IsNullOrWhiteSpace(Settings.Default.GamePath))
            {
                Settings.Default.GamePath = GetGameFolder();
                if (string.IsNullOrWhiteSpace(Settings.Default.GamePath))
                    Settings.Default.GamePath = SelectGameFolder();
                else
                    MessageBox.Show("Found game at " + Settings.Default.GamePath);
                Settings.Default.Save();
            }
        }

        public void UpdateButton(Button button, bool enabled)
        {
            if (enabled)
            {
                button.ForeColor = Color.Lime;
                button.FlatAppearance.MouseOverBackColor = Color.FromArgb(0, 40, 0);
                button.FlatAppearance.MouseDownBackColor = Color.Green;
            }
            else
            {
                button.ForeColor = Color.Green;
                button.FlatAppearance.MouseOverBackColor = Color.Black;
                button.FlatAppearance.MouseDownBackColor = Color.Black;
            }
        }

        public string GetGameFolder()
        {
            string libs;
            if (Environment.OSVersion.Platform == PlatformID.Win32NT)
                libs = @"C:\Program Files (x86)\Steam\steamapps\libraryfolders.vdf";
            else
                return null;
            foreach (var line in File.ReadAllLines(libs).Concat(new[] { @"C:\Program Files (x86)\Steam\" }))
            {
                var regex = new Regex("\\t\"\\d+\"\\t\\t\"(.+)\"");
                var match = regex.Match(line);
                if (!match.Success)
                    continue;
                string library = match.Groups[1].Value.Replace("\\\\", "\\");
                library += @"\steamapps\common\";
                if (File.Exists(library + @"Gamecraft\Gamecraft.exe"))
                    return library + "Gamecraft";
                if (File.Exists(library + @"RobocraftX\Gamecraft.exe"))
                    return library + "RobocraftX";
            }
            return libs;
        }

        public string SelectGameFolder()
        {
            var ofd = new OpenFileDialog();
            ofd.Filter = "Gamecraft executable|Gamecraft.exe";
            ofd.Title = "Game location";
            ofd.InitialDirectory = @"C:\Program Files (x86)\Steam\steamapps\common\";
            ofd.CheckFileExists = true;
            ofd.ShowDialog();
            if (string.IsNullOrWhiteSpace(ofd.FileName))
                return null;
            return Directory.GetParent(ofd.FileName).FullName;
        }

        private void playbtn_Click(object sender, EventArgs e)
        {

        }

        private void settingsbtn_Click(object sender, EventArgs e)
        {
            var sf = new SettingsForm();
            sf.ShowDialog(this);
        }
    }
}