Microsoft KB Archive/311284

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Article ID: 311284

Article Last Modified on 5/13/2007



APPLIES TO

  • Microsoft Visual Basic .NET 2002 Standard Edition
  • Microsoft Visual Basic .NET 2003 Standard Edition



This article was previously published under Q311284

For a Microsoft Visual C# .NET version of this article, see 312777.

IN THIS TASK

SUMMARY

REFERENCES

SUMMARY

This article demonstrates how to catch document events for the WebBrowser control in Visual Basic .NET.

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Requirements

The following list outlines the recommended hardware, software, network infrastructure, and service packs that you need:

  • Microsoft Visual Studio .NET
  • Microsoft Internet Explorer 5.5 Service Pack 2 (SP2) or later

This article assumes that you are familiar with the following topics:

  • Visual Studio .NET
  • Internet Explorer
  • WebBrowser control

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Description of the Technique

The WebBrowser control is an easy control to work with in Visual Studio .NET or earlier versions of Microsoft Visual Studio. However, you may find it more difficult to handle the events of a WebBrowser control in Visual Studio .NET.

The following event interface exposes most of the document events that you handle in your application:

Mshtml.HTMLDocumentEvents2_Event
                

To handle the event, you must create your own Sub procedure or function that you can call when the event occurs. You must match the signature of the event that fires. For example, the following Sub procedure handles the MouseOver event of the document:

Private Sub document_onmouseover(ByVal e As mshtml.IHTMLEventObj)
                

After the event handler is in place, you must hook the event. You can hook an event any time after the DocumentComplete event on the WebBrowser control fires. Here is the syntax of the hook:

AddHandler CType(document, _
mshtml.HTMLDocumentEvents2_Event).onmouseover, _
AddressOf Me.document_onmouseover
                

This code calls the AddHandler statement and uses the CType function to pass the event. The CType function casts the document object to the appropriate type (mshtml.HTMLDocumentEvents2_Event), and then the OnMouseOver event is passed from that. The Me.document_onmouseoverSub procedure is passed to the second parameter, the AddressOf statement, which provides the address of your handler.

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Create the Project and Add Code

In the following sample, the WebBrowser control browses to http://www.microsoft.com. After the page loads, the sample hooks the OnMouseOver and the OnClick events. The sample then adds text to a list box whenever the events fire.

  1. Start Visual Studio .NET.
  2. Create a new Windows Application project in Visual Basic .NET
  3. Add a reference to Microsoft.mshtml in the project.
  4. In the toolbox, click General.
  5. Right-click the open panel, and then click Customize Toolbox.
  6. Select the Microsoft Web Browser check box, and then click OK.
  7. In the toolbox, double-click Explorer.
  8. In the toolbox, click Windows Forms, and then double-click the ListBox control.
  9. Arrange the controls so that they are easy to view on the form.
  10. Add the following code to the top of AssemblyInfo.vb, replace the existing Import sentences

    Imports System
    Imports System.Drawing
    Imports System.Collections
    Imports System.ComponentModel
    Imports System.Windows.Forms
    Imports System.Data
    Imports System.Reflection
    Imports System.Runtime.InteropServices
    Imports System.Threading
    Imports System.Diagnostics
  11. Add the following code between Windows Form Designer generated code and End Class in the code view of Form1.vb Public

    Shared dwCookie2 As Integer
        Public Sub add_list(ByVal a As Object)
            ListBox1.Items.Insert(0, a)
        End Sub
        Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
            AxWebBrowser1.Navigate2("http://www.microsoft.com")
            Dim x As IEEvents = New IEEvents(AxWebBrowser1)
            x.fm = Me
        End Sub
    
        Private Sub AxWebBrowser1_Enter(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles AxWebBrowser1.Enter
    
        End Sub
    
        Private Sub AxWebBrowser1_DocumentComplete(ByVal sender As Object, ByVal e As AxSHDocVw.DWebBrowserEvents2_DocumentCompleteEvent) Handles AxWebBrowser1.DocumentComplete
            Dim doc As mshtml.HTMLDocument
            doc = AxWebBrowser1.Document
    
            AddHandler CType(doc, _
                mshtml.HTMLDocumentEvents2_Event).onclick, AddressOf Document_onclick
            AddHandler CType(doc, _
         mshtml.HTMLDocumentEvents2_Event).onmouseover, AddressOf Document_onmouseover
        End Sub
    
        Private Sub AxWebBrowser1_BeforeNavigate2(ByVal sender As Object, ByVal e As AxSHDocVw.DWebBrowserEvents2_BeforeNavigate2Event) Handles AxWebBrowser1.BeforeNavigate2
            Dim doc As mshtml.HTMLDocument
            doc = AxWebBrowser1.Document
    
            RemoveHandler CType(doc, _
                mshtml.HTMLDocumentEvents2_Event).onclick, _
                AddressOf Document_onclick
            RemoveHandler CType(doc, _
                mshtml.HTMLDocumentEvents2_Event).onmouseover, _
                AddressOf Document_onmouseover
        End Sub
        Private Sub Document_onmouseover(ByVal e As mshtml.IHTMLEventObj)
            ListBox1.Items.Insert(0, "onMouseOver: " & _
                e.srcElement.tagName.ToString())
        End Sub
        Private Function Document_onclick(ByVal e As mshtml.IHTMLEventObj) _
                As Boolean
            ListBox1.Items.Insert(0, "onClick: " & _
                e.srcElement.tagName.ToString())
            Return True
        End Function
  12. Add the following code after End Class

    Public Class IEHTMLDocumentEvents
        Implements mshtml.HTMLDocumentEvents2
        Public Sub onactivate(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onactivate
    
        End Sub
    
        Public Sub onafterupdate(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onafterupdate
    
        End Sub
    
        Public Function onbeforeactivate(ByVal pEvtObj As mshtml.IHTMLEventObj) As Boolean Implements mshtml.HTMLDocumentEvents2.onbeforeactivate
            Return True
        End Function
    
        Public Function onbeforedeactivate(ByVal pEvtObj As mshtml.IHTMLEventObj) As Boolean Implements mshtml.HTMLDocumentEvents2.onbeforedeactivate
            Return True
        End Function
    
        Public Sub onbeforeeditfocus(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onbeforeeditfocus
    
        End Sub
    
        Public Function onbeforeupdate(ByVal pEvtObj As mshtml.IHTMLEventObj) As Boolean Implements mshtml.HTMLDocumentEvents2.onbeforeupdate
            Return True
        End Function
    
        Public Sub oncellchange(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.oncellchange
    
        End Sub
    
        Public Function onclick(ByVal pEvtObj As mshtml.IHTMLEventObj) As Boolean Implements mshtml.HTMLDocumentEvents2.onclick
            Return True
        End Function
    
        Public Function oncontextmenu(ByVal pEvtObj As mshtml.IHTMLEventObj) As Boolean Implements mshtml.HTMLDocumentEvents2.oncontextmenu
            Return True
        End Function
    
        Public Function oncontrolselect(ByVal pEvtObj As mshtml.IHTMLEventObj) As Boolean Implements mshtml.HTMLDocumentEvents2.oncontrolselect
            Return True
        End Function
    
        Public Sub ondataavailable(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.ondataavailable
    
        End Sub
    
        Public Sub ondatasetchanged(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.ondatasetchanged
    
        End Sub
    
        Public Sub ondatasetcomplete(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.ondatasetcomplete
    
        End Sub
    
        Public Function ondblclick(ByVal pEvtObj As mshtml.IHTMLEventObj) As Boolean Implements mshtml.HTMLDocumentEvents2.ondblclick
            Return True
        End Function
    
        Public Sub ondeactivate(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.ondeactivate
    
        End Sub
    
        Public Function ondragstart(ByVal pEvtObj As mshtml.IHTMLEventObj) As Boolean Implements mshtml.HTMLDocumentEvents2.ondragstart
            Return True
        End Function
    
        Public Function onerrorupdate(ByVal pEvtObj As mshtml.IHTMLEventObj) As Boolean Implements mshtml.HTMLDocumentEvents2.onerrorupdate
            Return True
        End Function
    
        Public Sub onfocusin(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onfocusin
    
        End Sub
    
        Public Sub onfocusout(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onfocusout
    
        End Sub
    
        Public Function onhelp(ByVal pEvtObj As mshtml.IHTMLEventObj) As Boolean Implements mshtml.HTMLDocumentEvents2.onhelp
            Return True
        End Function
    
        Public Sub onkeydown(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onkeydown
    
        End Sub
    
        Public Function onkeypress(ByVal pEvtObj As mshtml.IHTMLEventObj) As Boolean Implements mshtml.HTMLDocumentEvents2.onkeypress
            Return True
        End Function
    
        Public Sub onkeyup(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onkeyup
    
        End Sub
    
        Public Sub onmousedown(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onmousedown
    
        End Sub
    
        Public Sub onmousemove(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onmousemove
    
        End Sub
    
        Public Sub onmouseout(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onmouseout
    
        End Sub
    
        Public Sub onmouseover(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onmouseover
    
        End Sub
    
        Public Sub onmouseup(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onmouseup
    
        End Sub
    
        Public Function onmousewheel(ByVal pEvtObj As mshtml.IHTMLEventObj) As Boolean Implements mshtml.HTMLDocumentEvents2.onmousewheel
            Return True
        End Function
    
        Public Sub onpropertychange(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onpropertychange
    
        End Sub
    
        Public Sub onreadystatechange(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onreadystatechange
    
        End Sub
    
        Public Sub onrowenter(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onrowenter
    
        End Sub
    
        Public Function onrowexit(ByVal pEvtObj As mshtml.IHTMLEventObj) As Boolean Implements mshtml.HTMLDocumentEvents2.onrowexit
            Return True
        End Function
    
        Public Sub onrowsdelete(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onrowsdelete
    
        End Sub
    
        Public Sub onrowsinserted(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onrowsinserted
    
        End Sub
    
        Public Sub onselectionchange(ByVal pEvtObj As mshtml.IHTMLEventObj) Implements mshtml.HTMLDocumentEvents2.onselectionchange
    
        End Sub
    
        Public Function onselectstart(ByVal pEvtObj As mshtml.IHTMLEventObj) As Boolean Implements mshtml.HTMLDocumentEvents2.onselectstart
            Return True
        End Function
    
        Public Function onstop(ByVal pEvtObj As mshtml.IHTMLEventObj) As Boolean Implements mshtml.HTMLDocumentEvents2.onstop
            Return True
        End Function
    End Class
    
    Public Class IEEvents
        Implements SHDocVw.DWebBrowserEvents2
        Public fm As Form1
        Private icp As System.Runtime.InteropServices.UCOMIConnectionPoint
        Private cookie As Integer = -1
        Private m_ie As AxSHDocVw.AxWebBrowser
    
        Public Sub New(ByRef ie As AxSHDocVw.AxWebBrowser)
            ' Call QueryInterface for IConnectionPointContainer
            m_ie = ie
            Dim icpc As System.Runtime.InteropServices.UCOMIConnectionPointContainer = CType(ie.GetOcx(), System.Runtime.InteropServices.UCOMIConnectionPointContainer)
            ' Find the connection point for the
            ' DWebBrowserEvents2 source interface
            Dim g As Guid = GetType(SHDocVw.DWebBrowserEvents2).GUID
            icpc.FindConnectionPoint(g, icp)
    
            'Pass a pointer to the host to the connection point
            icp.Advise(Me, cookie)
    
            ' Show the browser
            ie.Visible = True
            Dim oURL As Object = "http://www.microsoft.com"
            Dim oEmpty As Object = ""
            ie.Navigate2(oURL, oEmpty, oEmpty, oEmpty, oEmpty)
    
        End Sub
    
    
        Public Sub BeforeNavigate2(ByVal pDisp As Object, ByRef URL As Object, ByRef Flags As Object, ByRef TargetFrameName As Object, ByRef PostData As Object, ByRef Headers As Object, ByRef Cancel As Boolean) Implements SHDocVw.DWebBrowserEvents2.BeforeNavigate2
    
        End Sub
    
        Public Sub ClientToHostWindow(ByRef CX As Integer, ByRef CY As Integer) Implements SHDocVw.DWebBrowserEvents2.ClientToHostWindow
    
        End Sub
    
        Public Sub CommandStateChange(ByVal Command As Integer, ByVal Enable As Boolean) Implements SHDocVw.DWebBrowserEvents2.CommandStateChange
    
        End Sub
    
        Public Sub DocumentComplete(ByVal pDisp As Object, ByRef URL As Object) Implements SHDocVw.DWebBrowserEvents2.DocumentComplete
            Dim doc As mshtml.HTMLDocument = CType(CType(pDisp, SHDocVw.IWebBrowser2).Document, mshtml.HTMLDocument)
            Dim pConPtCon As System.Runtime.InteropServices.UCOMIConnectionPointContainer = CType(doc, System.Runtime.InteropServices.UCOMIConnectionPointContainer)
            Dim guid As Guid = System.Type.GetType("mshtml.HTMLDocumentEvents2").GUID
            Dim pConPt As System.Runtime.InteropServices.UCOMIConnectionPoint
            pConPtCon.FindConnectionPoint(guid, pConPt)
            Dim d As IEHTMLDocumentEvents = New IEHTMLDocumentEvents
            pConPt.Advise(d, Form1.dwCookie2)
    
            Dim iEvent As mshtml.HTMLDocumentEvents2_Event
            iEvent = CType(doc, mshtml.HTMLDocumentEvents2_Event)
            AddHandler iEvent.onclick, AddressOf ClickEventHandler
            AddHandler iEvent.onmouseover, AddressOf MouseOverEventHandler
        End Sub
        Private Function ClickEventHandler(ByVal e As mshtml.IHTMLEventObj) As Boolean
            fm.add_list(e.type + ":" + e.srcElement.tagName)
            Return True
        End Function
        Private Sub MouseOverEventHandler(ByVal e As mshtml.IHTMLEventObj)
            fm.add_list(e.type + ":" + e.srcElement.tagName)
        End Sub
        Public Sub DownloadBegin() Implements SHDocVw.DWebBrowserEvents2.DownloadBegin
    
        End Sub
    
        Public Sub DownloadComplete() Implements SHDocVw.DWebBrowserEvents2.DownloadComplete
    
        End Sub
    
        Public Sub FileDownload(ByRef Cancel As Boolean) Implements SHDocVw.DWebBrowserEvents2.FileDownload
    
        End Sub
    
        Public Sub NavigateComplete2(ByVal pDisp As Object, ByRef URL As Object) Implements SHDocVw.DWebBrowserEvents2.NavigateComplete2
    
        End Sub
    
        Public Sub NavigateError(ByVal pDisp As Object, ByRef URL As Object, ByRef Frame As Object, ByRef StatusCode As Object, ByRef Cancel As Boolean) Implements SHDocVw.DWebBrowserEvents2.NavigateError
    
        End Sub
    
        Public Sub NewWindow2(ByRef ppDisp As Object, ByRef Cancel As Boolean) Implements SHDocVw.DWebBrowserEvents2.NewWindow2
    
        End Sub
    
        Public Sub OnFullScreen(ByVal FullScreen As Boolean) Implements SHDocVw.DWebBrowserEvents2.OnFullScreen
    
        End Sub
    
        Public Sub OnMenuBar(ByVal MenuBar As Boolean) Implements SHDocVw.DWebBrowserEvents2.OnMenuBar
    
        End Sub
    
        Public Sub OnQuit() Implements SHDocVw.DWebBrowserEvents2.OnQuit
    
        End Sub
    
        Public Sub OnStatusBar(ByVal StatusBar As Boolean) Implements SHDocVw.DWebBrowserEvents2.OnStatusBar
    
        End Sub
    
        Public Sub OnTheaterMode(ByVal TheaterMode As Boolean) Implements SHDocVw.DWebBrowserEvents2.OnTheaterMode
    
        End Sub
    
        Public Sub OnToolBar(ByVal ToolBar As Boolean) Implements SHDocVw.DWebBrowserEvents2.OnToolBar
    
        End Sub
    
        Public Sub OnVisible(ByVal Visible As Boolean) Implements SHDocVw.DWebBrowserEvents2.OnVisible
    
        End Sub
    
        Public Sub PrintTemplateInstantiation(ByVal pDisp As Object) Implements SHDocVw.DWebBrowserEvents2.PrintTemplateInstantiation
    
        End Sub
    
        Public Sub PrintTemplateTeardown(ByVal pDisp As Object) Implements SHDocVw.DWebBrowserEvents2.PrintTemplateTeardown
    
        End Sub
    
        Public Sub PrivacyImpactedStateChange(ByVal bImpacted As Boolean) Implements SHDocVw.DWebBrowserEvents2.PrivacyImpactedStateChange
    
        End Sub
    
        Public Sub ProgressChange(ByVal Progress As Integer, ByVal ProgressMax As Integer) Implements SHDocVw.DWebBrowserEvents2.ProgressChange
    
        End Sub
    
        Public Sub PropertyChange(ByVal szProperty As String) Implements SHDocVw.DWebBrowserEvents2.PropertyChange
    
        End Sub
    
        Public Sub SetSecureLockIcon(ByVal SecureLockIcon As Integer) Implements SHDocVw.DWebBrowserEvents2.SetSecureLockIcon
    
        End Sub
    
        Public Sub StatusTextChange(ByVal Text As String) Implements SHDocVw.DWebBrowserEvents2.StatusTextChange
    
        End Sub
    
        Public Sub TitleChange(ByVal Text As String) Implements SHDocVw.DWebBrowserEvents2.TitleChange
    
        End Sub
    
        Public Sub UpdatePageStatus(ByVal pDisp As Object, ByRef nPage As Object, ByRef fDone As Object) Implements SHDocVw.DWebBrowserEvents2.UpdatePageStatus
    
        End Sub
    
        Public Sub WindowClosing(ByVal IsChildWindow As Boolean, ByRef Cancel As Boolean) Implements SHDocVw.DWebBrowserEvents2.WindowClosing
    
        End Sub
    
        Public Sub WindowSetHeight(ByVal Height As Integer) Implements SHDocVw.DWebBrowserEvents2.WindowSetHeight
    
        End Sub
    
        Public Sub WindowSetLeft(ByVal Left As Integer) Implements SHDocVw.DWebBrowserEvents2.WindowSetLeft
    
        End Sub
    
        Public Sub WindowSetResizable(ByVal Resizable As Boolean) Implements SHDocVw.DWebBrowserEvents2.WindowSetResizable
    
        End Sub
    
        Public Sub WindowSetTop(ByVal Top As Integer) Implements SHDocVw.DWebBrowserEvents2.WindowSetTop
    
        End Sub
    
        Public Sub WindowSetWidth(ByVal Width As Integer) Implements SHDocVw.DWebBrowserEvents2.WindowSetWidth
    
        End Sub
    End Class
    

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Additional Notes

  • This process is the same if you automate Internet Explorer. Replace AxWebBrowser1 with your local variable name for Internet Explorer.
  • This sample does not consider framesets. When you navigate to a frameset, you may not see any events in your application. If necessary in your application, you must add code to handle the frameset possibility.

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REFERENCES

For more information about the WebBrowser control, as well as the methods, the properties, and the events that the WebBrowser control exposes, refer to the following MSDN documentation:

For more information about developing Web-based solutions for Microsoft Internet Explorer, visit the following Microsoft Web sites:

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Additional query words: web browser

Keywords: kbhowtomaster kbwebbrowser KB311284