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FriendFeedClass for Displaying Modal HTML Dialogs
How to Use Modal HTML Dialogs
The function SHOWHTMLDIALOGFN in mshtml.dll is the means to display a HTML dialog. But it requires the usual COM stuff - conversions of strings and all those things. In order to simplify all of this, I developed a class (CHtmlDialog). All the COM stuff is hidden and thus, the class is easy to incorporate into almost any application.
A Simple Case of Using CHtmlDialog
As a simple case suppose you want to use it as an about box. All you have to do is to write an HTML file and include it in the resource file say as IDR_ABOUT_HTM. Your OnAppAbout function would look like.
void CHDDemoApp::OnAppAbout()
{
CHtmlDialog dlg(IDR_ABOUT_HTM, AfxGetMainWnd());
dlg.DoModal();
}
The constructor also allows you to pass string resource IDs or URLs to display. See the Demo program for details. Just by using this code and including graphics and sound in the HTML resource you can have sophisticated displays and graphics in your about box without any coding on your part. But there all lots more you can do.
Passing Parameters to the Dialog Box
Just displaying an HTML resource is good but sometimes you may want to do more like you may want to pass some parameters from the application (like product id, licensing etc.) to be displayed in the about box. You can pass a string type or a variant type data to the dialog box. As an example I want to pass product id, user name, company name and the application version to be displayed.
In my C++ program I would add the following code.
void CHDDemoApp::OnDemoParam1()
{
CHtmlDialog dlg(IDR_ABOUT1_HTM, AfxGetMainWnd());
CString str = m_strProductID //product ID
+ ";"+ m_strUserName //User Licensed + ";"
+ m_strCompanyName //Company Name
+ ";" + m_strAppVersion;
dlg.SetParam(str);
dlg.DoModal();
}
The C++ side is over. In the actual HTML page we are displaying we have to include some javascript/vbscript functions. If you are not familiar with IE4 DHTML you can skip this. Whatever parameter that is passed to the CHtmlDialog become the dialogArguments property of the window object in the HTML that is being displayed. So the javascript function would look something like this :
function getParameters()
{
var args = new Array();
args = window.dialogArguments.split(";");
//Now display in the document
Productid.innerText = args[0];
UserName.innerText = args[1];
CompanyName.innerText = args[2];
AppVersion.innerText = args[3];
}
Note that Productid, UserName, CompanyName and AppVersion are IE4 DOM elements.
Getting Return Values From the Dialog Box
We have seen that by using both Javascript and C++ we can get something more. How about passing parameters let the user do something in the dialog as result of which we get some return values and pass it back to C++ program? As an example I let the user modify the Username an the company name in the demo program. Again we have to do something with Javascript and with C++ as described below.
When the HTML window is being closed in the handler of onunload, we place the following code.
function window_onclose()
{
window.returnValue = UserName.value + ";" + CompanyName.value;
}
Just by setting the return Value property the value is conveyed
back to C++ code. The return Value can be any variant. In our C++
code we handle return values by calling function GetReturnString or
GetReturnVariant.
dlg.DoModal(); //Display the dialog CString str = dlg.GetReturnString(); //Now handle the return value in whatever way
Setting the Dialog Size
Upto this point the question never occured how we can set the size. In the above samples the size was set by using the following tag in the HTML
<HTML style="width: 25em; height: 30em>
CHtmlDialog provides a simple method for setting the size without specifying in the HTML tags. Just call the function SetDialogSize(int nWidth, int nHeight); There is another function which can be used to set the size and that is SetOptions(LPCTSTR lpszOptions);. The option string is of the format "dialogWidth: xxx; dialogHeight: xxx". Refer to description of showmodalDialog function in Internet client SDK for more details.
Demo Program
The demo program illustrates all these clearly. Run the demo program. You will find a menu Demo. Select the demo which you want to see. In the Demo program I have only one HTML resource page and I adjust the contents depending on the parameters being send to the program. (A bit of Javascript). The explanation of the Demo is found in a scrolling marquee on the top of the HTML dialog you open. Just try it and see it. Feel free to consult me for any doubts.
Conclusion
My class hides all the internal details of the implementations and thus can be used without any knowledge of the functions of Internet Client SDK used. The demo program covers almost all the cases. If you don't have any idea of Jvascript or IE4 DOM it is useful to through Internet Client SDK. Together with HTML and C++ you can provide very rich GUI.
Notes
This project requires
- 1. Internet Explorer 4.0 (or greater). (IE4.0 SP1 is recommended)
- 2. VC++ 6.0 (or greater) or VC++ 5.0 (with Internet Client SDK)
Comments
Freeze loading several times "No Parameters" HTML Demo...
Posted by Legacy on 10/21/2003 12:00amOriginally posted by: Arthur
Hi,
I have had the same problem...
Execute your HDDemo and select
Demo -> No Parameters
On Win98, after about 65 times, your HTML sample will freezes.
On WinXP or Win2K, after about 538 times, your HTML sample will freezes.
Is there a solution for this???
thanks a Lot...
ReplyPassing Arguments
Posted by Legacy on 05/12/2003 12:00amOriginally posted by: Sri Ram Kanth
ReplyHow do i make it modeless browser
Posted by Legacy on 04/29/2003 12:00amOriginally posted by: Rajesh
I want to use this control over the dialog box as a control so what all changes i need to make.
ReplyHow to display a mht file.
Posted by Legacy on 07/26/2002 12:00amOriginally posted by: away
ShowHtmlDlg or CHtmlDlg can only display hta / html file.
Replyhow to display a mht file?
Changing the ICON
Posted by Legacy on 06/08/2002 12:00amOriginally posted by: Sukhpal Singh
There is a way to change the icon of the HTML dialog but this involves editing the MSHTML.DLL and redistributing the DLL with your application. There are certain restrictions:
1. You can't put the edited version of the MSHTML.DLL in you application directory you will have to place the DLL in windows\system directory, which means you have to replace the original one.
2. Because MSHTML.DLL is used by many other applications such as internet explorer, once you have cahnged the icon in MSHTML.DLL it will change the icon in many other programs as well. This is not something the users of your application will want.
IF you want to do it here are the steps:
1. Download Resource Hacker at http://www.users.on.net/johnson/resourcehacker/
2. Unzip it and run the program.
3. Load the MSHTML.DLL by opening it from the File -> Open menu.
4. Expand the Icon tree.
5. Find the ie icon. Replace it by click on Action -> Replace Icon menu.
6. Choose your icon and click replace. Click Save As from the menu. NOTE: dont' click save.
Voila there you have it. Run your application and see it for yourself.
PLEASE: this is not the proper way of doing it if there is a better way please let me know.
ReplyClass for Displaying Modal HTML Dialogs
Posted by Legacy on 04/10/2002 12:00amOriginally posted by: Alia D
Can you implement this code in Java instead?
Replygood one
Posted by Legacy on 02/28/2002 12:00amOriginally posted by: AMIT
ReplyCustomize MSTML editor using VB
Posted by Legacy on 02/18/2002 12:00amOriginally posted by: Giri Rajan
Hai,
I would like to know how to set and edit properties of HTML elements Through Visual Basic. For eg i want to cahnge the size of the Text box or change Font style in text.
Replyi would like to have properties as we have in Visual Inter Dev or Front Page.
Can't get to compile!
Posted by Legacy on 02/07/2002 12:00amOriginally posted by: Sibilant
Compiling...
StdAfx.cpp
Compiling...
ChildFrm.cpp
DLGHTML.cpp
C:\WAREZ\C++\Current sound Project\c to HTML\DLGHTML.cpp(80) : error C2664: 'long (struct HWND__ *,struct IMoniker *,struct tagVARIANT *,unsigned short *,struct tagVARIANT *)' : cannot convert parameter 4 from 'char *' to 'unsigned short *'
Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast
HDDemo.cpp
HDDemoDoc.cpp
HDDemoView.cpp
MainFrm.cpp
Generating Code...
Error executing cl.exe.
HDDemo.exe - 1 error(s), 0 warning(s)
Any suggestions would be greatly appreciated.
Sibilant
ReplyMy HTML is in memory, not a resource or a file
Posted by Legacy on 12/18/2001 12:00amOriginally posted by: Rajiv Bhagwat
How to use this to show the HTML which has been loaded (and possibly changed) in the memory?
ReplyLoading, Please Wait ...