I've been reading and following up on how to write a BHO in IE using C# and I can register it just fine and run it but it only works properly when in the first window\tab I've got open.
I know aspects of it are triggering in every new window but the changes don't "stick" or apply if they're affecting the DOM. So, for example, I load a page that displays some text in the top of the page, it will always be there in the first tab but all the others it may be there are first then disappear or not show up at all.
I'm using c# 4 on Win7x64 using IE11. Protected mode doesn't appear to affect this one way or the other.
My code is just a mix of what's up here tutorial wise, so nothing fancy.
namespace IEExtention
{
[
ComVisible(true),
Guid("e8483cfd-d208-45f7-837c-3cdca573d84a"),
ClassInterface(ClassInterfaceType.None)
]
public class BHO : IObjectWithSite
{
private WebBrowser webBrowser;
private static readonly ILog log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
private object mySite;
public int SetSite(object site)
{
if (site != null)
{
mySite = site;
webBrowser = (WebBrowser)site;
webBrowser.DocumentComplete +=
new DWebBrowserEvents2_DocumentCompleteEventHandler(
this.OnDocumentComplete);
}
else
{
webBrowser.DocumentComplete -=
new DWebBrowserEvents2_DocumentCompleteEventHandler(
this.OnDocumentComplete);
webBrowser = null;
}
return 0;
}
public int GetSite(ref Guid guid, out IntPtr ppvSite)
{
IntPtr punk = Marshal.GetIUnknownForObject(webBrowser);
int hr = Marshal.QueryInterface(punk, ref guid, out ppvSite);
Marshal.Release(punk);
return hr;
}
public void OnDocumentComplete(object pDisp, ref object URL)
{
log.Debug("test");
if (pDisp != mySite)
{
return;
}
HTMLDocument document = (HTMLDocument)this.webBrowser.Document;
document.title = "Hello, StackOverflow!";
try
{
IHTMLDOMNode greetings = document.createTextNode("Hi there!");
IHTMLDOMNode body = document.body as IHTMLDOMNode;
body.insertBefore(greetings, body.firstChild);
}
catch (Exception e)
{
//whoo!!
}
}
It's had me stumped for a few days as even something as changing the document.title doesn't always stay.
I was able to work around this issue by threading my BHO and sleeping it for about half a second. Interestingly enough I needed to up the sleep to about 1.5 seconds to deal with outside links (say something coming from outlook) to load up and get everything to display.
I'm not sure if this is the best way to do it but it solved my problem with it only working in the first tab.
Related
We have a WPF with a tab control being the primary UI for displaying customer details, each open customer gets its own tab.
Within the customer tabs we have another tab control that allows switching between various subsets of information, 2 of these use the Webbrowser control with IHTMLChangeSink functionality to monitor for hidden divs meant to trigger logic in the app.
Previously we were experiencing a very large memory leak when a Customer tab was closed, the cause of this was found to be the event handler created by RegisterForDirtyRange. To resolve the memory leak the Dispose methods were modified to call UnregisterForDirtyRange, using AutoIT to rapidly open and close customer tabs we were able to prove that the memory leak was fixed; this was done on a developer class machine.
Once this change was rolled out to testers we started seeing the application crash, in the event log we saw that the call to UnregisterForDirtyRange was throwing a ComException with HRESULT E_FAIL. Since we never saw this come up on the developer hardware and on the testers machines there was no guaranteed way to produce the crash I am thinking that there is some kind of race condition that is amplified when run on less powerful hardware.
Given this information my question is with regards to the internal workings of the Unregister call, can anyone think of what might be causing this exception?
My initial thought was that maybe the Notify method was running at the time of dispose so I tried introducing a lock between the dispose and notify but this didn't change anything.
Here is a stripped down version of the tab control that wraps the Web Browser:
public partial class BrowserTabWidget : BrowserWidget, IHTMLChangeSink
{
private static Guid _markupContainer2Guid = typeof(IMarkupContainer2).GUID;
private IMarkupContainer2 _container;
private uint _cookie;
public BrowserTabWidget()
{
InitializeComponent();
if (!System.ComponentModel.DesignerProperties.GetIsInDesignMode(this))
{
Loaded += OnLoaded;
}
}
protected override void DisposeControls()
{
if (_container != null)
{
_container.UnRegisterForDirtyRange(_cookie);
Marshal.ReleaseComObject(_container);
}
WebBrowser.LoadCompleted -= OnWebBrowserLoadCompleted;
WebBrowser.Dispose();
}
public override string CurrentUri
{
get { return (string)GetValue(CurrentUriProperty); }
set
{
NavigateTo(value);
SetValue(CurrentUriProperty, value);
}
}
private void NavigateTo(string value)
{
WebBrowser.Navigate(new Uri(value));
}
public static readonly DependencyProperty CurrentUriProperty = DependencyProperty.Register("CurrentUri", typeof(string), typeof(BrowserTabWidget), new FrameworkPropertyMetadata(CurrentUriChanged));
public static void CurrentUriChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var widget = (BrowserTabWidget)d;
d.Dispatcher.BeginInvoke(
DispatcherPriority.Normal,
new Action(() => widget.NavigateTo(e.NewValue.ToString())));
}
private void InitializeWebBrowser()
{
WebBrowser.LoadCompleted += OnWebBrowserLoadCompleted;
WebBrowser.Navigate(new Uri(viewModel.InitialUrl));
}
void OnWebBrowserLoadCompleted(object sender, System.Windows.Navigation.NavigationEventArgs e)
{
_container = GetMarkupContainer();
_container.RegisterForDirtyRange(this, out _cookie);
}
private void OnLoaded(object sender, RoutedEventArgs e)
{
Loaded -= OnLoaded;
Load();
}
private void Load()
{
InitializeWebBrowser();
}
private IMarkupContainer2 GetMarkupContainer()
{
var oDocument = WebBrowser.Document as IHTMLDocument2;
var pDocument = Marshal.GetIUnknownForObject(oDocument);
IntPtr pMarkupContainer;
Marshal.QueryInterface(pDocument, ref _markupContainer2Guid, out pMarkupContainer);
var oMarkupContainer = Marshal.GetUniqueObjectForIUnknown(pMarkupContainer);
Marshal.Release(pDocument);
Marshal.Release(pMarkupContainer);
return (IMarkupContainer2)oMarkupContainer;
}
public void Notify()
{
var document = WebBrowser.Document as HTMLDocument;
if (document != null)
{
//Parse Dom for hidden elements and trigger appropriate event handler
}
}
}
Hmya, E_FAIL, the curse of COM. Useless to ever diagnose anything, it is just a teacher's grade for the quality of the error reporting. I wrote the same code in Winforms to get something to testable, no repro. It is nevertheless very easy to force a repro. Given that the method takes only one argument, there's only one thing that can go wrong:
if (_container != null)
{
_container.UnRegisterForDirtyRange(_cookie);
_container.UnRegisterForDirtyRange(_cookie); // Kaboom!!!
Marshal.ReleaseComObject(_container);
}
Bad cookie. Criminal that they don't return E_INVALIDARG btw.
I could not test your exact code of course, it does have problems. Most severe one I see and the repro case is that there is no protection against calling DisposeControls() more than once. In general it is never wrong to dispose objects more than once, I have no insight if that's a realistic failure mode in your project. Otherwise very simple to protect yourself against this. Including catch-and-swallow code:
protected override void DisposeControls()
{
if (_container == null) return;
try {
_container.UnRegisterForDirtyRange(_cookie);
}
catch (System.Runtime.InteropServices.COMException ex) {
if (ex.ErrorCode != unchecked((int)0x80004005)) throw;
// Log mishap...
}
finally {
Marshal.ReleaseComObject(_container);
_container = null;
_cookie = 0;
WebBrowser.LoadCompleted -= OnWebBrowserLoadCompleted;
WebBrowser.Dispose();
}
}
Another thing I noticed in my test version of your code is that you don't appear to have any protection against the browser navigating to another page by any other means than WebBrowser.Navigate(). Or the LoadCompleted event firing more than once, it does for the stackoverflow.com home page for example. Or any web page that uses frames. That's a leak. Make it resilient by having your OnWebBrowserLoadCompleted() event handler also unregister the cookie if it is set.
I've got a little problem and tried to solve it now for nearly 6 to 8 hours but I didn't find any matching answer. I'm a complete newbie to WPF, so please point me any errors I made.
At first I have the following in my App.xaml.cs:
namespace WpfVideowand
{
public partial class App : Application
{
...
private void Application_Startup(object sender, StartupEventArgs e)
{
foreach (System.Windows.Forms.Screen MyScreen in System.Windows.Forms.Screen.AllScreens)
{
List<string> MyStrings = Xml.GetScreens(i);
if (MyStrings[1] == "true")
{
OpenWindow(MyScreen, MyStrings[0], i);
}
i++;
Shelf MyShelf = new Shelf(MyScreen, i, MyStrings[0]);
MyShelf.Show();
}
}
private void OpenWindow(System.Windows.Forms.Screen myScreen, string configName, int screenNumber)
{
Shelf NewShelf = new Shelf(myScreen, screenNumber, configName);
}
}
}
And inside the Shelf.xaml.cs it looks this way:
namespace WpfVideowand
{
public partial class Shelf : Window
{
[DllImport("user32.dll")]
static extern IntPtr GetActiveWindow();
System.Windows.Forms.Screen _Screen { get; set; }
...
public Shelf(System.Windows.Forms.Screen myScreen, int screenNumber, string configName)
{
InitializeComponent();
_Screen = myScreen;
ShowOnMonitor(screenNumber);
...
}
private void ShowOnMonitor(int screenNumber)
{
System.Windows.Forms.Screen[] ScreenArray;
ScreenArray = System.Windows.Forms.Screen.AllScreens;
int XCoord = Convert.ToInt32(ScreenArray[screenNumber].Bounds.Left);
this.Left = XCoord;
int YCoord = Convert.ToInt32(ScreenArray[screenNumber].Bounds.Top);
this.Top = XCoord;
IntPtr active = GetActiveWindow();
System.Windows.Application.Current.Windows.OfType<Window>().SingleOrDefault(window => new WindowInteropHelper(window).Handle == active).Name = "Monitor" + screenNumber.ToString();
System.Windows.Application.Current.Windows.OfType<Window>().SingleOrDefault(window => new WindowInteropHelper(window).Handle == active).WindowState = WindowState.Maximized;
}
...
}
}
The way described above worked fine in Windows Forms Application. In WPF I have the problem, that I get the error message, that rectangle (the window) would have no Top or Left property.
I even tried it in some other ways, like creating with
System.Windows.Forms.Screen _screen = System.Windows.Forms.Screen.FromControl(this);
an object, that would have .Top and .Left. But there I get the message, that I cannot convert a Shelf-object into a System.Windows.Forms.Control.
Anyone a suggestion, how I could make my Screens appear on the monitor where it should be?
Ok, I found it myself...
For anyone who is interested in finding some answers to this problem here it is:
At first, see that you have the correct reference implemented. For this you need System.Drawing and System.Windows.Forms. (Afterwards you have to declare many things explicit, like System.Windows.Controls.Button instead of Button, etc.)
Then see that you start the app with something like Startup="Application_Startup" and not an uri, because you want to start many forms and not only one.
Afterwards be absolutly sure to NOT set the Windowstyle to maximized in the XAML (this did cost me nearly 4 hours. In between i grew 56 grey hairs). Use this in the Code-Behind:
System.Windows.Application.Current.Windows.OfType().SingleOrDefault(window => new WindowInteropHelper(window).Handle == active).WindowState = WindowState.Maximized;
I'm developing a BHO in CSHARP and I have an issue in onDocumentComplete method.
It runs on every IFRAME that the main document loads. How can I avoid it? I only want to handle events in the main window.
public void OnDocumentComplete(object pDisp, ref object URL)
{
document = (HTMLDocument)webBrowser.Document;
document.body.style.backgroundColor = "red";
}
Compare this.site with pDisp. If they're equal, then the code is running in the main frame:
public void OnDocumentComplete(object pDisp, ref object URL)
{
if (pDisp != this.site) {
// Ignore subframes
return;
}
document = (HTMLDocument)webBrowser.Document;
document.body.style.backgroundColor = "red";
}
I create an instance of IE outside my program, which the program finds and attaches to correctly. I set up my event handler and tell the program to advance to the login screen. The DocumentCompleted handle is supposed to fire when the web page is completely loaded, but mine seems to be firing before the new page has appeared.. The handle only fires once (meaning there is only one frame?).
This code executes fine if I modify it to work straight from the login page also.. Am I doing something wrong? Thanks for any assistance :)
Process.Start(#"IESpecial.exe");
SHDocVw.ShellWindows allBrowsers = new SHDocVw.ShellWindows();
while (true)
{
foreach (SHDocVw.WebBrowser ie in allBrowsers)
{
if (ie.LocationURL == "http://website/home.asp")
{
loggingIn = true;
webBrowser = ie;
webBrowser.DocumentComplete += new SHDocVw.DWebBrowserEvents2_DocumentCompleteEventHandler(webBrowser1_DocumentCompleted);
webBrowser.Navigate("http://website/logon.asp");
return;
}
}
Thread.Sleep(10);
}
}
private void webBrowser1_DocumentCompleted(object pDisp, ref object URL)
{
//we are attempting to log in
if (loggingIn)
{
mshtml.HTMLDocumentClass doc = (mshtml.HTMLDocumentClass)webBrowser.Document;
mshtml.HTMLWindow2 window = (mshtml.HTMLWindow2)doc.IHTMLDocument2_parentWindow;
doc.getElementById("Username").setAttribute("value", "MLAPAGLIA");
doc.getElementById("Password").setAttribute("value", "PASSWORD");
window.execScript("SubmitAction()", "javascript");
loggingIn = false;
return;
}
The 'click sound' in question is actually a system wide preference, so I only want it to be disabled when my application has focus and then re-enable when the application closes/loses focus.
Originally, I wanted to ask this question here on stackoverflow, but I was not yet in the beta. So, after googling for the answer and finding only a little bit of information on it I came up with the following and decided to post it here now that I'm in the beta.
using System;
using Microsoft.Win32;
namespace HowTo
{
class WebClickSound
{
/// <summary>
/// Enables or disables the web browser navigating click sound.
/// </summary>
public static bool Enabled
{
get
{
RegistryKey key = Registry.CurrentUser.OpenSubKey(#"AppEvents\Schemes\Apps\Explorer\Navigating\.Current");
string keyValue = (string)key.GetValue(null);
return String.IsNullOrEmpty(keyValue) == false && keyValue != "\"\"";
}
set
{
string keyValue;
if (value)
{
keyValue = "%SystemRoot%\\Media\\";
if (Environment.OSVersion.Version.Major == 5 && Environment.OSVersion.Version.Minor > 0)
{
// XP
keyValue += "Windows XP Start.wav";
}
else if (Environment.OSVersion.Version.Major == 6)
{
// Vista
keyValue += "Windows Navigation Start.wav";
}
else
{
// Don't know the file name so I won't be able to re-enable it
return;
}
}
else
{
keyValue = "\"\"";
}
// Open and set the key that points to the file
RegistryKey key = Registry.CurrentUser.OpenSubKey(#"AppEvents\Schemes\Apps\Explorer\Navigating\.Current", true);
key.SetValue(null, keyValue, RegistryValueKind.ExpandString);
isEnabled = value;
}
}
}
}
Then in the main form we use the above code in these 3 events:
Activated
Deactivated
FormClosing
private void Form1_Activated(object sender, EventArgs e)
{
// Disable the sound when the program has focus
WebClickSound.Enabled = false;
}
private void Form1_Deactivate(object sender, EventArgs e)
{
// Enable the sound when the program is out of focus
WebClickSound.Enabled = true;
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
// Enable the sound on app exit
WebClickSound.Enabled = true;
}
The one problem I see currently is if the program crashes they won't have the click sound until they re-launch my application, but they wouldn't know to do that.
What do you guys think? Is this a good solution? What improvements can be made?
const int FEATURE_DISABLE_NAVIGATION_SOUNDS = 21;
const int SET_FEATURE_ON_PROCESS = 0x00000002;
[DllImport("urlmon.dll")]
[PreserveSig]
[return: MarshalAs(UnmanagedType.Error)]
static extern int CoInternetSetFeatureEnabled(int FeatureEntry,
[MarshalAs(UnmanagedType.U4)] int dwFlags,
bool fEnable);
static void DisableClickSounds()
{
CoInternetSetFeatureEnabled(FEATURE_DISABLE_NAVIGATION_SOUNDS,
SET_FEATURE_ON_PROCESS,
true);
}
I've noticed that if you use WebBrowser.Document.Write rather than WebBrowser.DocumentText then the click sound doesn't happen.
So instead of this:
webBrowser1.DocumentText = "<h1>Hello, world!</h1>";
try this:
webBrowser1.Document.OpenNew(true);
webBrowser1.Document.Write("<h1>Hello, world!</h1>");
You disable it by changing Internet Explorer registry value of navigating sound to "NULL":
Registry.SetValue("HKEY_CURRENT_USER\\AppEvents\\Schemes\\Apps\\Explorer\\Navigating\\.Current","","NULL");
And enable it by changing Internet Explorer registry value of navigating sound to "C:\Windows\Media\Cityscape\Windows Navigation Start.wav":
Registry.SetValue("HKEY_CURRENT_USER\\AppEvents\\Schemes\\Apps\\Explorer\\Navigating\\.Current","","C:\Windows\Media\Cityscape\Windows Navigation Start.wav");
Definitely feels like a hack, but having done some research on this a long time ago and not finding any other solutions, probably your best bet.
Better yet would be designing your application so it doesn't require many annoying page reloads.. for example, if you're refreshing an iframe to check for updates on the server, use XMLHttpRequest instead. (Can you tell that I was dealing with this problem back in the days before the term "AJAX" was coined?)
If you want to use replacing Windows Registry, use this:
// backup value
RegistryKey key = Registry.CurrentUser.OpenSubKey(#"AppEvents\Schemes\Apps\Explorer\Navigating\.Current");
string BACKUP_keyValue = (string)key.GetValue(null);
// write nothing
key = Registry.CurrentUser.OpenSubKey(#"AppEvents\Schemes\Apps\Explorer\Navigating\.Current", true);
key.SetValue(null, "", RegistryValueKind.ExpandString);
// do navigation ...
// write backup key
RegistryKey key = Registry.CurrentUser.OpenSubKey(#"AppEvents\Schemes\Apps\Explorer\Navigating\.Current", true);
key.SetValue(null, BACKUP_keyValue, RegistryValueKind.ExpandString);