C#

[DllImport("user32")]
        static extern IntPtr GetForegroundWindow();

        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = false)]
        static extern IntPtr SendMessage(IntPtr hWnd, Int32 Msg,
        IntPtr wParam, StringBuilder lParam);

        [DllImport("user32.dll", SetLastError = true)]
        static extern IntPtr FindWindowEx(IntPtr parentHandle,
        IntPtr childAfter, string className, IntPtr windowTitle);

        //c po sur elle marche po xD
        private const int WM_GETTEXT = 0x000D;

        public static string getChromeURL()
        {
            uint MAX_PATH = 255;
            IntPtr hChrome, hAddressBox;
            hChrome = GetForegroundWindow();

            hAddressBox = FindWindowEx(hChrome, IntPtr.Zero,
                      "Chrome_AutocompleteEditView", IntPtr.Zero);

            StringBuilder sb = new StringBuilder(256);

            SendMessage(hAddressBox, WM_GETTEXT, (IntPtr)MAX_PATH, sb);

            string s = sb.ToString().Trim(new Char[] { ' ', '\0', '\n' });
            return s;
        }