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Introduction.

This article describes how to use a simple control to add a web browser to an application. It also goes on to show how to control the browser and enable editing. Don't forget at the very minimum you will need IE4 installed on the target system. CHtmlCtrl was created by Paul DiLascia and the full article can be found at Microsoft Systems Journal.

Using CHtmlCtrl.

• Start by including the following headers.

#include <afxhtml.h>        // MFC support for Web browser
#include <mshtml.h>         //IWeb objects
#include <atlconv.h>        //Conversion routines

• Add the HtmlCtrl.cpp and HtmlCtrl.h files to the project with menu option "Project->Add to Project->Files". 
• Add a static control to a dialog and size it as required. 
• Lets call this control IDC_STATIC_BROWSER. 
• To the dialog header include the control and make an object to hold it.

#include "HtmlCtrl.h"                               //Web browser control
...
class ...
{
...
//Attributes
private:
    CHtmlCtrl   m_Browser;                          //Web browser object.
...
}

• Next create the object and load a page in the OnInitDialog();.

    m_Browser.CreateFromStatic( IDC_STATIC_BROWSER, this );
    m_Browser.Navigate( _T("www.mctainsh.com") );

Load from an internal Resource.

We shall compile an html file and image into the application and load it at start-up. 

• Put an html file and image in the res directory. 
• Add the following to the app.RC2 file.

/////////////////////////////////////////////////////////////////////////////
// Add manually edited resources here...
ABOUT.HTM       HTML DISCARDABLE "res\\about.htm"
FOX.GIF         HTML DISCARDABLE "res\\fox.gif"

• Change OnInitDialog(); to the following.

    m_Browser.CreateFromStatic( IDC_STATIC_BROWSER, this );
    m_Browser.LoadFromResource( _T("ABOUT.HTM") );

Make CHtmlCtrl talk to application.

By adding a prefix to the hyper link, the web control can call code in the application. Here app: is used as the link prefix. When CHtmlCtrl::OnBeforeNavigate2 detects this it passes the command string on to CHtmlCtrl::OnAppCmd, where actions can be performed according to the input string.

The HTML is like this.

<a href="app:JustDoIt">Make it happen</a>

Processing.

void CHtmlCtrl::OnAppCmd(LPCTSTR lpszWhere)
{
    ...
    if( _tcscmp( _T("JustDoIt"), lpszWhere )==0 ) 
    {
        RunSweatShop();
    }   
    ...

How to make a HTML editor.

This web browser control can be used to edit and create HTML with the following code. This will put the control in design mode.

    IDispatch* pDispatch = m_Browser.GetHtmlDocument();
    //Only if a resource or web page is loaded can we get the document
    if( pDispatch != NULL )
    {
        IHTMLDocument2* pHtmlDoc;
        HRESULT hr = pDispatch->QueryInterface( __uuidof( IHTMLDocument2 ), (void**)&pHtmlDoc );
        pDispatch->Release();
        if( SUCCEEDED( hr ) )
        {
            pHtmlDoc->put_designMode(L"On"); 
            pHtmlDoc->Release();
        }
    }

How to modify append the page content from the app.

It is possible to dynamically modify the content of the web browser dynamically from the application. This is done by reading the document body changing it and writing it back. The following code reads the body and adds a message to the end with the current time in it.

    IDispatch* pDispatch = m_Browser.GetHtmlDocument();
    //Only if a resource or web page is loaded can we get the document
    if( pDispatch != NULL )
    {
        IHTMLDocument2* pHtmlDoc;
        HRESULT hr = pDispatch->QueryInterface( __uuidof( IHTMLDocument2 ), (void**)&pHtmlDoc );
        pDispatch->Release();
        if( SUCCEEDED( hr ) )
        {
            //Get access to the internal document
            IHTMLElement *pElement;
            hr = pHtmlDoc->get_body( &pElement );
            if( SUCCEEDED( hr ) )
            {
                //Extract the data
                USES_CONVERSION;
                BSTR bsMainText;
                pElement->get_innerHTML( &bsMainText );
                CString sBody( OLE2T(bsMainText) );
                SysFreeString( bsMainText );

                //Append the new text
                sBody += _T("<p>Just added this line at ");
                sBody += CTime::GetCurrentTime().Format( _T("%H:%M:%S") );
                sBody += _T("</p>");

                //Assign the new text
                bsMainText = SysAllocString( T2OLE(sBody) );
                pElement->put_innerHTML( bsMainText );
                SysFreeString( bsMainText );
                pElement->Release();
            }
        }
    }

How to view the app's resource.

It is possible to view the resources compiled into an application with a web browser. For the demo application use the following line entered as the web address. 

res://D:\SRC\TryHtml\Debug\TryHtml.exe/about.htm