Article ID: 238313
Article Last Modified on 6/29/2004
APPLIES TO
- Microsoft Visual Basic 4.0 Standard Edition
- Microsoft Visual Basic 4.0 Professional Edition
- Microsoft Visual Basic 4.0 32-Bit Enterprise Edition
- Microsoft Visual Basic 5.0 Learning Edition
- Microsoft Visual Basic 5.0 Professional Edition
- Microsoft Visual Basic 5.0 Enterprise Edition
This article was previously published under Q238313
SYMPTOMS
In an article entitled "Accessing the Internet Explorer Document Object Model From Visual Basic 5.0", provided with the July 1999 edition of the Microsoft Developer Network (MSDN), Figure 4 includes sample code for "Inspecting Elements in an HTML Document". When this code executes the following error may occur:
CAUSE
The code sample does not correctly handle cases where frames exist on a Web page.
RESOLUTION
The following code replaces the code sample in Figure 4. It modifies the RecurseFrames and FillTree procedures to correctly handle cases where frames exist on a Web page:
Option Explicit
Private Sub cmdBack_Click()
On Error Resume Next
WebBrowser1.GoBack
End Sub
Private Sub cmdForward_Click()
On Error Resume Next
WebBrowser1.GoForward
End Sub
Private Sub cmdGo_Click()
WebBrowser1.Navigate txtAddress
End Sub
Private Sub Form_Load()
WebBrowser1.Navigate "http://www.microsoft.com"
End Sub
Private Sub WebBrowser1_DocumentComplete(ByVal pDisp As Object, _
URL As Variant)
On Error Resume Next
If (pDisp Is WebBrowser1.object) Then
' DocumentComplete event is fired for each frame on a page
' this condition means that the main document is fully loaded
' and you can use brwWebBrowser.Document property
txtAddress = WebBrowser1.LocationURL
Me.Caption = WebBrowser1.LocationName
txtText = ""
tvTreeView.Nodes.Clear
RecurseFrames WebBrowser1.Document, Nothing
End If
End Sub
Private Sub RecurseFrames(ByVal iDoc As HTMLDocument, _
ByVal iNode As Node)
Dim I As Integer
Dim Range As IHTMLTxtRange
Dim Title As String
Dim TextInfo As String
Dim tvNode As Node
On Error Resume Next
Title = iDoc.Title
If Title = "" Then
Title = iDoc.parentWindow.Name
If Title = "" Then Title = iDoc.location
End If
If iNode Is Nothing Then
' if this is the first time, add a root node
Set tvNode = tvTreeView.Nodes.Add(, , , Title)
Else
Set tvNode = tvTreeView.Nodes.Add(iNode.Index, tvwChild, , Title)
End If
TextInfo = "Frame: " & Title & vbCrLf & "{" + vbCrLf
' check to see if the document has a BODY
If iDoc.body.tagName = "BODY" Then
' fill the tree with following collections
FillTree iDoc, "OBJECT", tvNode, "ActiveX Controls"
FillTree iDoc, "A", tvNode, "Anchors"
FillTree iDoc, "IMG", tvNode, "Images"
FillTree iDoc, "", tvNode, "All"
' use the text range object to get text out of BODY
Set Range = iDoc.body.createTextRange
TextInfo = TextInfo & Range.Text & vbCrLf
Set Range = Nothing
ElseIf iDoc.frames.length > 0 Then
' fill the tree with each Frame in the
' collection and traverse each Frame
For I = 0 To iDoc.frames.length - 1
TextInfo = TextInfo & "FRAME: " & _
iDoc.frames(I).Document.nameProp & vbCrLf
Dim doc As New HTMLDocument
Dim eCollection As IHTMLElementCollection
Dim uElement As HTMLUnknownElement
Set eCollection = iDoc.frames(I).Document.All
For Each uElement In eCollection
If uElement.tagName = "HTML" Then
doc.All(0).insertAdjacentHTML "BeforeBegin", _
uElement.innerHTML
doc.Title = "Frame: " & _
iDoc.frames(I).Document.nameProp
FillTree doc, "FRAME", tvNode, "FRAME"
RecurseFrames doc, tvNode
Set doc = Nothing
End If
Next uElement
Next I
End If
txtText.Text = txtText.Text & TextInfo & "}" & vbCrLf
End Sub
Private Sub FillTree(iDoc As HTMLDocument, iMatchTag As String, _
iNode As Node, iCategory As String)
Dim Element As Object
Dim Info As String
Dim tvNode As Node
Dim tvCatNode As Node
On Error Resume Next
Set tvCatNode = Nothing
For Each Element In iDoc.All
' if the tag is the desired tag or all tags are desired
If iMatchTag = "" Or Element.tagName = iMatchTag Then
Info = Element.tagName & " "
' display information based on the tagName of the element
If Element.tagName = "IMG" Then
Info = Info & Element.href
ElseIf Element.tagName = "A" Then
Info = Info & Element.innerText & _
" (" & Element.href & ")"
ElseIf Element.tagName = "INPUT" Then
Info = Info & Element.Type
ElseIf Element.tagName = "META" Then
Info = Info & Element.nodeName
ElseIf Element.tagName = "FRAMESET" Then
Info = Info & Element.Name
ElseIf Element.tagName = "FRAME" Then
Info = Info & ": " & Element.src
Else
Info = Info & Element.Id
End If
If tvCatNode Is Nothing Then
' add the category node if its not there
Set tvCatNode = tvTreeView.Nodes.Add(iNode.Index, _
tvwChild, , iCategory)
End If
Set tvNode = tvTreeView.Nodes.Add(tvCatNode.Index, _
tvwChild, , Info)
End If
If Element.tagName = "FRAME" Then
' traverse each Frame in the collection
Dim I As Long
For I = 0 To iDoc.frames.length - 1
' process the current Frame contents
If iDoc.frames(I).Document.nameProp _
= Element.Document.nameProp Then
Dim doc As New HTMLDocument
Dim eCollection As IHTMLElementCollection
Dim uElement As HTMLUnknownElement
Set eCollection = iDoc.frames(I).Document.All
For Each uElement In eCollection
If uElement.tagName = "HTML" Then
doc.All(0).insertAdjacentHTML "BeforeBegin", _
uElement.innerHTML
doc.Title = "Frame: " & _
iDoc.frames(I).Document.nameProp
RecurseFrames doc, tvNode
Set doc = Nothing
End If
Next uElement
End If
Next I
End If
Next
End Sub
MORE INFORMATION
Use of the code included in this article is not supported. This sample is not supported by Microsoft Corporation. It is provided "AS IS".
REFERENCES
For more information about this topic, please see the article titled "Accessing the Internet Explorer Document Object Model From Visual Basic 5.0" included in the July 1999 edition of the Microsoft Developer Network (MSDN). For additional information, please see the following article in the Microsoft Knowledge Base:
162719 HOWTO: Use the WebBrowser Control from Visual Basic 5.0
Additional query words: vba
Keywords: kbwebbrowser kbfile kbprb KB238313
