how to get URL form any web browser (like firefox,ie,google chrome,...) in C#

DdeClient dde = new DdeClient(browser, "WWW_GetWindowInfo");
dde.Connect();
string url = dde.Request("URL", int.MaxValue);
string[] text = url.Split(new string[] { "\",\"" }, StringSplitOptions.RemoveEmptyEntries);
dde.Disconnect();
return text[0].Substring(1);
 
Download NDde dll and add reference, and use as name space
 
//===========Get URL of All Tabs From IE ======================
 
SHDocVw.InternetExplorer browser;
string myLocalLink;
mshtml.IHTMLDocument2 myDoc;
SHDocVw.ShellWindows shellWindows = new SHDocVw.ShellWindows();
string filename;
foreach (SHDocVw.InternetExplorer ie in shellWindows)
{
filename = System.IO.Path.GetFileNameWithoutExtension(ie.FullName).ToLower();
if ((filename == "iexplore"))
{
browser = ie;
myDoc = browser.Document;
myLocalLink = myDoc.url;
MessageBox.Show(myLocalLink);
}

Request.Url.AbsoluteUri.ToString()

public string GetChormeURL(string ProcessName)
{
    string ret = "";
    Process[] procs = Process.GetProcessesByName(ProcessName);
    foreach (Process proc in procs)
    {
        // the chrome process must have a window
        if (proc.MainWindowHandle == IntPtr.Zero)
        {
            continue;
        }
        //AutomationElement elm = AutomationElement.RootElement.FindFirst(TreeScope.Children,
        //         new PropertyCondition(AutomationElement.ClassNameProperty, "Chrome_WidgetWin_1"));
        // find the automation element
        AutomationElement elm = AutomationElement.FromHandle(proc.MainWindowHandle);

        // manually walk through the tree, searching using TreeScope.Descendants is too slow (even if it's more reliable)
        AutomationElement elmUrlBar = null;
        try
        {
            // walking path found using inspect.exe (Windows SDK) for Chrome 43.0.2357.81 m (currently the latest stable)
            // Inspect.exe path - C://Program files (X86)/Windows Kits/10/bin/x64
            var elm1 = elm.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.NameProperty, "Google Chrome"));
            if (elm1 == null) { continue; } // not the right chrome.exe
            var elm2 = TreeWalker.RawViewWalker.GetLastChild(elm1); // I don't know a Condition for this for finding
            var elm3 = elm2.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.NameProperty, ""));
            var elm4 = TreeWalker.RawViewWalker.GetNextSibling(elm3); // I don't know a Condition for this for finding
            var elm5 = elm4.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.ToolBar));
            var elm6 = elm5.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.NameProperty, ""));
            elmUrlBar = elm6.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Edit));
        }
        catch
        {
            // Chrome has probably changed something, and above walking needs to be modified. :(
            // put an assertion here or something to make sure you don't miss it
            continue;
        }

        // make sure it's valid
        if (elmUrlBar == null)
        {
            // it's not..
            continue;
        }

        // elmUrlBar is now the URL bar element. we have to make sure that it's out of keyboard focus if we want to get a valid URL
        if ((bool)elmUrlBar.GetCurrentPropertyValue(AutomationElement.HasKeyboardFocusProperty))
        {
            continue;
        }

        // there might not be a valid pattern to use, so we have to make sure we have one
        AutomationPattern[] patterns = elmUrlBar.GetSupportedPatterns();
        if (patterns.Length == 1)
        {
            try
            {
                ret = ((ValuePattern)elmUrlBar.GetCurrentPattern(patterns[0])).Current.Value;
                return ret;
            }
            catch { }
            if (ret != "")
            {
                // must match a domain name (and possibly "https://" in front)
                if (Regex.IsMatch(ret, @"^(https:\/\/)?[a-zA-Z0-9\-\.]+(\.[a-zA-Z]{2,4}).*$"))
                {
                    // prepend http:// to the url, because Chrome hides it if it's not SSL
                    if (!ret.StartsWith("http"))
                    {
                        ret = "http://" + ret;
                    }
                    return ret;
                }
            }
            continue;
        }
    }
    return ret;
}