• Access the automation model and the scripting model in Microsoft Internet Explorer from a contained Visual C++ .NET UserControl control.
• Enumerate all controls, links, and other tags in a page and in sub pages. This includes an algorithm that you can recursively enumerate floating frames and framesets.

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Requirements

• Microsoft Visual Studio .NET 2003 or Microsoft Visual Studio 2005
• Microsoft Internet Explorer (Programming) version 5.5 or later

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Download the UserControl control

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About the UserControl control

RecurseFrames function

void RecurseFrames( mshtml::HTMLDocument * iDoc , TreeNode * iNode )
{
	String* Title = S"";  
	String* tagName = S"";  
	
	TreeNode * TNode;
	
	mshtml::IHTMLElementCollection *pColl = 0;
	mshtml::FramesCollection* framesCol = 0;
	
	Object *nullObject = 0;
	
	Int32 i;

	//Get the document title
	if( iDoc != NULL )
	{
		Title = iDoc->get_title();
		if (Title->Length == 0)
			Title = S"Untitled Document";
	}

	TNode = new TreeNode(Title);
	
	// Add a root or a child node
	if (iNode == 0) 
		treeView1->Nodes->Add(TNode); // Root node
	else
		iNode->Nodes->Add(TNode);     // Child node
	
	if (iDoc != NULL)
	{
		DocCollection(iDoc, S"OBJECT", TNode, S"ActiveX Controls");
		DocCollection(iDoc, S"A", TNode, S"Anchors");
		DocCollection(iDoc, S"IMG", TNode, S"Images");
		DocCollection(iDoc, S"", TNode, S"All");
		
		// Get the Frames collection
		framesCol = iDoc->get_frames();

		// Recurse all the frames
		if (framesCol != NULL)
		{
			int nFrameLength = framesCol->length;
			for (i = 0; i < nFrameLength; i++)
			{
				Object* objNum = __box(i);
				Object* objNextFrame = framesCol->item(&objNum);

				// Get the HTMLWindow2 object
				mshtml::HTMLWindow2* objWin2 = 
					__try_cast<mshtml::HTMLWindow2*>(objNextFrame);

				// Get the HTMLDocument object
				mshtml::HTMLDocument* objDoc = 
					__try_cast<mshtml::HTMLDocument*>(objWin2->document);

				// Make the call to Recurse frames
				RecurseFrames( objDoc, TNode );
			}
		}
	}
}

1. Click Project, and then click <ProjectName> Properties.
   
   Note <ProjectName> is a placeholder for the name of the project.
2. Expand Configuration Properties, and then click General.
3. Click to select Common Language Runtime Support, Old Syntax (/clr:oldSyntax) in the Common Language Runtime support project setting in the right pane, click Apply, and then click OK.

DocCollection function

void DocCollection(mshtml::HTMLDocument * iDoc, String * iMatchTag ,TreeNode * iNode,String * iCategory)
{
	TreeNode * TNode;
	TreeNode * CatNode;
	int i;
	String * Name;
	mshtml::IHTMLElementCollection *pColl = 0;
	Object *nullObject = 0;
	CatNode = 0;

	if( iDoc != NULL )
	{
		// Get a pointer to all elements collections.
		pColl = iDoc->get_all();
		
		// Loop through the Elements Collection.
		int j = pColl->length;

		for (i=0;i < j ; i++)
		{
		    	
			// Read Tag Name of Each element in the Element Collection.
			Object *objNum = __box(i);
			String * str = __try_cast<String*>( __try_cast<mshtml::IHTMLElement*>(iDoc->get_all()->item(objNum,nullObject))->get_tagName());

			//if the tag is the that you want tag or you want all tags
			if (iMatchTag == S"" || String::Compare(str,iMatchTag)== 0)
			{
				Name = S"";
				if (String::Compare(str,S"IMG")== 0 ||  String::Compare(str,S"A")== 0)
				{
					Name = __try_cast<String*>(__try_cast<mshtml::IHTMLAnchorElement*>(iDoc->get_all()->item(objNum,nullObject))->get_href());
				}
				if (String::Compare(str,S"OBJECT")== 0)
				{
					Name = __try_cast<String*>(__try_cast<mshtml::IHTMLElement*>(iDoc->get_all()->item(objNum,nullObject))->get_id());
				}
		    	
				Name = String::Concat(str,S" ", Name); 
		    	
				//'add the category node if it is not there
				if (CatNode == 0)
				{
					CatNode = new TreeNode(iCategory);
					iNode->Nodes->Add(CatNode);
				}
				TNode = new TreeNode(Name);
				CatNode->Nodes->Add(TNode);
			}
		}
		// if there are no elements in the document, add category nodes
		if (j == 0)
		{
			//'add the category node if its not there
			if (CatNode == 0)
			{
				CatNode = new TreeNode(iCategory);
				iNode->Nodes->Add(CatNode);
			}
			TNode = new TreeNode(Name);
			CatNode->Nodes->Add(TNode);
		}
	}
}

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Run the sample

Method 1

1. Start the .NET Framework configuration tool, Mscorcfg.msc.
2. Expand each element in the following path: My Computer/Runtime Security Policy/Machine/Code Groups/All Code/LocalIntranet_Zone.
3. Right-click the LocalIntranet_Zone node, and then click New.
4. Name the new code group TestVCNetCtrl, and then click Next.
5. On the Choose a condition type page in the Create Code Group dialog box, click URL as the condition type, and then type http://ServerName/* in the URL text box.
6. Click Next to continue to the Assign a Permission Set to the Code Group page.
7. Click to select Use existing permission set:, and then click FullTrust.
8. Click Next, and then click Finish.
9. Copy all the files in the debug directory to any location under http://ServerName, and then locate http://ServerName/testautoie.htm.

Method 2

1. Start Mscorcfg.msc.
2. Expand each element in the My Computer/Runtime Security Policy path.
3. Right-click the Runtime Security Policy node, and then click Trust Assembly to open the Trust an Assembly dialog box.
4. Click to select Make changes to this computer, and then click Next to continue to the next page.
5. Type the full path of the Assembly (for example, type: http://ServerName/VCNetCtrl.dll) in the appropriate field, or locate the Assembly.
6. Click Next to proceed to the Choose the Minimum Level of Trust for this Assembly page of the Trust an Assembly dialog box.
7. Adjust the trust level to Full Trust, click Next, and then click Finish.
8. Copy all the files in the debug directory to any location under http://ServerName, and then locate http://ServerName/testautoie.htm.

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Technical notes

• Make sure that you add a reference to the Microsoft HTML Object Library (MSHTML.dll) in your project.
  
  Note All post-Beta 2 releases of the Microsoft .NET Framework Software Development Kit (SDK) now include a primary interop assembly for Mshtml.dll. However, any organization that distributes the .NET Framework through the .NET Framework Redistributable must not depend on the existence of this interop assembly on clients. You can find the assembly that is named Microsoft.Mshtml.dll in the following location: INSTALL_DIR\Microsoft.NET\Primary Interop, where INSTALL_DIR is the installation directory for the .NET Framework. You can reference this from your projects and deploy your application on any system where the .NET Framework SDK is pre-installed.
• This is an unmanaged COM component that allows only full-trusted callers. Therefore, you must have Full Trust code access permissions to run the control. This is discussed in the Run the sample section of this article.
• .NET UserControl control instances cannot directly access the Document Object Model of their hosting page, as ActiveX controls do. To work around this issue, you must expose a property in your UserControl control that retrieves the HTML document from the page. This is demonstrated in the following sample code:

  private:
  mshtml::HTMLDocument* docVal;
  	
  public:
  
  __property mshtml::HTMLDocument* get_DocVal()
  {
      return docVal;
  }
  __property void set_DocVal(mshtml::HTMLDocument* val)
  {
      docVal = (val);
  } 
  	

• The following is the syntax to access the control from an HTML page:

  <OBJECT id="theId" classid="YourControl.dll#NameSpace.NameOfControl">
  </OBJECT>

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