Retrieve current URL from C# windows forms application

Here is a code based on Microsoft UI Automation:

public static string GetChromeUrl(Process process)
{
    if (process == null)
        throw new ArgumentNullException("process");

    if (process.MainWindowHandle == IntPtr.Zero)
        return null;

    AutomationElement element = AutomationElement.FromHandle(process.MainWindowHandle);
    if (element == null)
        return null;

    AutomationElement edit = element.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Edit));
    return ((ValuePattern)edit.GetCurrentPattern(ValuePattern.Pattern)).Current.Value as string;
}

public static string GetInternetExplorerUrl(Process process)
{
    if (process == null)
        throw new ArgumentNullException("process");

    if (process.MainWindowHandle == IntPtr.Zero)
        return null;

    AutomationElement element = AutomationElement.FromHandle(process.MainWindowHandle);
    if (element == null)
        return null;

    AutomationElement rebar = element.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.ClassNameProperty, "ReBarWindow32"));
    if (rebar == null)
        return null;

    AutomationElement edit = rebar.FindFirst(TreeScope.Subtree, new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Edit));

    return ((ValuePattern)edit.GetCurrentPattern(ValuePattern.Pattern)).Current.Value as string;
}

public static string GetFirefoxUrl(Process process)
{
    if (process == null)
        throw new ArgumentNullException("process");

    if (process.MainWindowHandle == IntPtr.Zero)
        return null;

    AutomationElement element = AutomationElement.FromHandle(process.MainWindowHandle);
    if (element == null)
        return null;

    AutomationElement doc = element.FindFirst(TreeScope.Subtree, new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Document));
    if (doc == null)
        return null;

    return ((ValuePattern)doc.GetCurrentPattern(ValuePattern.Pattern)).Current.Value as string;
}

You can use the UI Spy tool to understand the visual hierarchy for all 3 browsers. You may need to adapt things to make sure it really work in your specific cases, but you should get the general idea with these samples.

And an example that dumps all urls for all the 3 types of process (IE, FF, CH) currently running in the system:

static void Main(string[] args)
{
    foreach (Process process in Process.GetProcessesByName("firefox"))
    {
        string url = GetFirefoxUrl(process);
        if (url == null)
            continue;

        Console.WriteLine("FF Url for '" + process.MainWindowTitle + "' is " + url);
    }

    foreach (Process process in Process.GetProcessesByName("iexplore"))
    {
        string url = GetInternetExplorerUrl(process);
        if (url == null)
            continue;

        Console.WriteLine("IE Url for '" + process.MainWindowTitle + "' is " + url);
    }

    foreach (Process process in Process.GetProcessesByName("chrome"))
    {
        string url = GetChromeUrl(process);
        if (url == null)
            continue;

        Console.WriteLine("CH Url for '" + process.MainWindowTitle + "' is " + url);
    }
}