Add several User32.dll NativeMethods

src/Tgstation.Server.Host/NativeMethods.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Runtime.InteropServices;
+using System.Text;
 
 namespace Tgstation.Server.Host
 {
@@ -8,6 +9,42 @@ namespace Tgstation.Server.Host
 	/// </summary>
 	static class NativeMethods
 	{
+		/// <summary>
+		/// See https://docs.microsoft.com/en-us/windows/desktop/api/winuser/nf-winuser-getwindowthreadprocessid
+		/// </summary>
+		[DllImport("user32.dll")]
+		public static extern int GetWindowThreadProcessId(IntPtr hWnd, out int lpdwProcessId);
+
+		/// <summary>
+		/// See https://docs.microsoft.com/en-us/windows/desktop/api/winuser/nf-winuser-findwindoww
+		/// </summary>
+		[DllImport("user32.dll", CharSet = CharSet.Unicode)]
+		public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
+
+		/// <summary>
+		/// See https://docs.microsoft.com/en-us/windows/desktop/api/winuser/nf-winuser-sendmessage
+		/// </summary>
+		[DllImport("user32.dll")]
+		public static extern int SendMessage(IntPtr hWnd, int wMsg, IntPtr wParam, IntPtr lParam);
+
+		/// <summary>
+		/// See https://msdn.microsoft.com/en-us/library/ms633493(v=VS.85).aspx
+		/// </summary>
+		public delegate bool EnumWindowProc(IntPtr hwnd, IntPtr lParam);
+
+		/// <summary>
+		/// See https://docs.microsoft.com/en-us/windows/desktop/api/winuser/nf-winuser-enumchildwindows
+		/// </summary>
+		[DllImport("user32")]
+		[return: MarshalAs(UnmanagedType.Bool)]
+		public static extern bool EnumChildWindows(IntPtr window, EnumWindowProc callback, IntPtr lParam);
+
+		/// <summary>
+		/// See https://docs.microsoft.com/en-us/windows/desktop/api/winuser/nf-winuser-getwindowtextw
+		/// </summary>
+		[DllImport("user32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
+		public static extern int GetWindowText(IntPtr hWnd, StringBuilder lpString, int nMaxCount);
+
 		/// <summary>
 		/// See https://msdn.microsoft.com/en-us/library/windows/desktop/aa378184(v=vs.85).aspx
 		/// </summary>