DCS.cs

using System;
using System.Threading.Tasks;
using System.Numerics; // Vector
using System.Runtime.InteropServices; // DLL business
using System.Diagnostics; // Process

public class DCS
{
    [DllImport("user32.dll")]
    static extern IntPtr GetForegroundWindow();

    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool GetWindowRect(IntPtr hWnd, out RECT lpRect);

    [StructLayout(LayoutKind.Sequential)]
    public struct RECT
    {
        public int Left;        // x position of upper-left corner
        public int Top;         // y position of upper-left corner
        public int Right;       // x position of lower-right corner
        public int Bottom;      // y position of lower-right corner
    }

    public static async void Monitor(Fingers parent)
    {
        Vector4 result = new Vector4();
        Vector4 lastResult = new Vector4();
        IntPtr hWnd;
        RECT rect;

        while (true)
        {
            hWnd = GetDCSWindow();
            if (hWnd != IntPtr.Zero)
            {
                GetWindowRect(hWnd, out rect);
                result.X = rect.Left;
                result.Y = rect.Top;
                result.Z = rect.Bottom - rect.Top; // height
                result.W = rect.Right - rect.Left; // width

                if (result.Z > 600 && !lastResult.Equals(result))
                {
                    parent.HandleDCSWindow(result);
                    lastResult = result;
                }
            }

            await Task.Delay(5000);
        }
    }

    public static IntPtr GetDCSWindow()
    {
        IntPtr hWnd = IntPtr.Zero;
        
        foreach (Process pList in Process.GetProcesses())
        {
          if (pList.MainWindowTitle.Equals("")) continue;

          if (pList.ProcessName.Equals("DCS") &&
              pList.MainWindowTitle.Contains("Digital Combat Simulator") &&
              !pList.MainWindowTitle.Contains("_server"))
          {
            return pList.MainWindowHandle;
          }
        }

        return hWnd;
    }
}