Marc Gregoire’s Blog

C++0x adds a new looping structure: the Range-Based for loop. This makes it easier to loop over elements of lists. It works with standard C arrays and types that have begin() and end() functions returning iterators like almost all STL containers.

Below is an example of a range-based for loop looping over a standard C-style array, incrementing each value by 1.

int myArray[3] = {1, 2, 3};
for(auto& el : myArray) {
    ++el;
}

Note that this example also uses the auto type deduction introduced in C++0x.
Now it’s only waiting until the C++ compilers start supporting it

Microsoft has just released a refreshed version of the Windows Phone Developer Tools CTP. The biggest change is that it is now compatible with the final version of Visual Studio 2010 RTM

The CTP includes the following components:

• Visual Studio 2010 Express for Windows Phone CTP
• Windows Phone Emulator CTP
• Silverlight for Windows Phone CTP
• XNA Game Studio 4.0 CTP

Get it here.

I was technical editor for the book “Ivor Horton’s Beginning Visual C++ 2010“, published by Wiley. According to the author:

I would particularly like to thank my technical editor, Marc Gregoire, for doing such an outstanding job of reviewing the text and checking out all the code fragments and examples in the book. His many constructive comments and suggestions for better ways of presenting the material has undoubtedly made the book a much better tutorial.

Below is a description of what you can expect from the book.

By following author Ivor Horton’s accessible tutorial approach and detailed examples you can quickly become an effective C++ programmer. Thoroughly updated for the 2010 release, this book introduces you to the latest development environment and teached you how to build real-world applications using Visual C++. With this book by your side, you are well on your way to writing applications in both versions of C++ and becoming a successful C++ programmer.

Ivor Horton’s Beginning Visual C++ 2010:

• Teaches the essentials of C++ programming using both of the C++ language technologies supported by Visual C++ 2010.
• Shares techniques for finding errors in C++ programs and explains general debugging principles.
• Discusses the structure and essential elements that are present in every Windows application.
• Demonstrates how to develop native Windows applications using the Microsoft Foundation Classes.
• Guides you through designing and creating substantial Windows applications in both C++ and C++/CLI.
• Features numerous working examples and exercises that help build programming skills.

A few days ago, Microsoft released Visual Studio 2010. Unfortunately, for the time being, this final version is not compatible with the Windows Phone Developer Tools CTP that was released a while ago. According to Charlie Kindel:

“If you install the retail (RTM) release of Visual Studio 2010 on the same machine on which you already have the Windows Phone Developer Tools CTP, you will be unable to build your Windows Phone projects.  Further, while the Windows Phone project type will continue to appear in the File/New dialog, you will not be able to build Windows Phone 7 applications.”

The Windows Phone Developer Tools are being updated and a version that supports the final version of Visual Studio 2010 will be released in a few weeks.

In the meantime, Charlie Kindel recommends the following if you need the retail version of Visual Studio 2010 together with the Windows Phone Developer Tools CTP:

• Install Visual Studio 2010 to a VPC image
• Install Visual Studio 2010  on another machine

Note that installing the Windows Phone Developer Tools CTP to a VPC image is not supported.

Register here to be informed when an updated version of the Windows Phone Developer Tools is released.

Today, Microsoft released Visual Studio 2010 and the .NET Framework 4. A lot of new features are included. One of them is a completely new editor.

“Visual Studio 2010 and .NET Framework 4 have something for every developer. The new editor, now using Windows Presentation Foundation, delivers a more flexible, feature-rich environment that supports concepts such as the use of multiple monitors. This enables a developer to have one monitor with code, another with the user interface designer, and yet another with database structure.”

Visual C++ 2010 also includes a lot of new features, some of them are:

• MSBuild and multi-targeting
• IntelliSense and Browsing (#include auto completion, call hierarchy, red squiggles, find all references, class wizard)
• C++ compiler changes (static_assert, auto keyword, lambda, decltype, rvalue references)
• Ribbon designer
• Deployment changes
• Task dialog support
• Restart manager support

Read the full press release here or watch the keynote.

Later this week, Silverlight 4 will also be released to the web (RTW). At that time, an update for Visual Studio 2010 will also become available that will allow you to develop applications using Silverlight 4.

A friend of mine, Marius Bancila, wrote several blog posts with details about new features in Visual C++ 2010.

He touches the following features:

• MSBuild and multi-targeting
• IntelliSense and Browsing (#include auto completion, call hierarchy, red squiggles, find all references, class wizard)
• C++ compiler changes (static_assert, auto keyword, lambda, decltype, rvalue references)
• Ribbon designer
• Deployment changes
• Task dialog support
• Restart manager support

You can read his posts here. They give you a good idea of new features in VC++ 2010

Now that you know “How To Use the Microsoft WebBrowser Control to Render HTML from Memory” and “How To Navigate to an Anchor in the Microsoft WebBrowser Control when Rendering HTML from Memory“, it’s time to learn how to handle custom URL protocols to tailor the navigation inside the WebBrowser Control to fit your application. The following demonstrates a custom URL protocol called “app”:

<a href="app://some.target">Test</a>

When you would put this link in a normal Internet Explorer window, clicking the link will generate an error because IE does not know how to handle the APP protocol. The name APP is chosen arbitrarily. You can use whatever you want. Handling these custom protocols in your C++ application is actually pretty simple and it doesn’t even involve any real COM coding like in the previous articles. The first thing you need to do is to add a handler for the BeforeNavigate2 handler. Open the resource editor and open your dialog with the WebBrowser control. Right click the WebBrowser control and select “Add Event Handler…”. Select “BeforeNavigate2” as message type, select the appropriate class and click “Add and Edit”. This handler will be called right before the WebBrowser control will navigate to a new page. To handle the custom protocol, implement the handler as follows:

void CMyDlg::BeforeNavigate2Explorer(LPDISPATCH pDisp, VARIANT* URL, VARIANT* Flags,
    VARIANT* TargetFrameName, VARIANT* PostData, VARIANT* Headers, BOOL* Cancel)
{
    const wchar_t* cpszProtocolName = L"app";
    const wchar_t* cpszProtocolSeparator = L"://";

    // We only handle VT_BSTR.
    if (URL->vt != VT_BSTR)
        return;

    // Check the protocol of the URL
    CString str = URL->bstrVal;
    int iPos = str.Find(cpszProtocolSeparator);
    if (iPos == -1)    // Unable to figure out protocol
        return;

    // Extract protocol and check if it's our APP protocol
    CString strProtocol = str.Mid(0, iPos);
    if (strProtocol.CompareNoCase(cpszProtocolName))
        return;    // not our APP protocol

    // It's our APP protocol, so start processing it.
    // Start by preventing Internet Explorer from handling the protocol.
    *Cancel = TRUE;

    // Extract target URL
    CString strTarget = str.Mid(iPos+wcslen(cpszProtocolSeparator));
    strTarget.TrimRight(L"/");

    // Now we are ready to process our protocol.
    // For this demo, I just render a new HTML page with the name
    // of the URL target without the protocol part of the string.
    CString strHTML;
    strHTML.Format(L"My APP protocol processing: \"%s\"", strTarget);
    WriteHTML(strHTML);
}

The flow is pretty straightforward. The URL protocol is extracted; if it’s not our protocol, we let Internet Explorer handle the URL for us. If it is our custom “APP” protocol, we first set Cancel to TRUE which will prevent Internet Explorer from handling this URL protocol. Once that is done, we are completely free to implement the handling of the “APP” protocol however we want. As demonstration I just write a new HTML document from memory which will just mention that we are processing an “APP” protocol URL and that will also display the target part of the URL.

You can quickly test the code with the following piece of HTML rendered from memory:

WriteHTML(L"<html><body>"
    L"<p><a href=\"app://FirstAppProtocolTestLink\">test 1</a></p>"
    L"<p><a href=\"APP://SecondAppProtocolTestLink.Withdots\">test 2</a></p>"
    L"</body></html>");

Run the application, click on the “test 1″ or “test 2″ link and see what happens.

That’s it for handling custom URL protocols in C++

In my previous blog entry titled “How To Use the Microsoft WebBrowser Control to Render HTML from Memory” I described a method how you could use the Microsoft WebBrowser Control to display HTML from memory. One commenter said that it was not possible to navigate to an anchor in the body onload handler. I did some research and it seems all navigation within the rendered page is not working. For example, the following piece of HTML code will not work correctly:

<a href="#n25">Jump to anchor n25</a>
<a name="n25">25</a>

It took me a while to find a workaround, so that’s why I’m posting it now for other people to use. Basically, we cannot use the standard navigation techniques. I tried several possible workaround and the only one that I got working properly is by manually scrolling the window until the requested anchor is visible. It sounds complicated, but it really works pretty nicely. I wrote this little wrapper function to do all the hard work.

void CMyDlg::ScrollToAnchor(const wchar_t* anchor)
{
    IDispatch* pHtmlDoc = m_explorer.get_Document();
    if (!pHtmlDoc)
        return;
    CComPtr<IHTMLDocument2> doc2;
    doc2.Attach((IHTMLDocument2*)pHtmlDoc);
    if (doc2)
    {
        CComPtr<IHTMLElementCollection> anchors;
        HRESULT hr = doc2->get_anchors(&anchors);
        if (SUCCEEDED(hr) && anchors)
        {
            _variant_t index = 0;
            _variant_t str = anchor;
            IDispatch *pdisp;
            hr = anchors->item(str, index, &pdisp);
            if (SUCCEEDED(hr) && pdisp)
            {
                CComPtr<IHTMLElement> el;
                hr = pdisp->QueryInterface(IID_IHTMLElement, (void**)&el);
                if (SUCCEEDED(hr) && el)
                {
                    long yTotal = 0;
                    while (1)
                    {
                        long y;
                        el->get_offsetTop(&y);
                        yTotal += y;
                        CComPtr<IHTMLElement> el2;
                        hr = el->get_offsetParent(&el2);
                        if (SUCCEEDED(hr) && el2)
                            el = el2;
                        else
                            break;
                    }
                    CComPtr<IHTMLWindow2> wnd;
                    hr = doc2->get_parentWindow(&wnd);
                    if (SUCCEEDED(hr) && wnd)
                        wnd->scrollTo(0, yTotal);
                }
            }
        }
    }
}

What it does is it gets a pointer to the document. Then gets a list of all the anchors in the document and get the anchor with the given name out of that list. Once we have the target element, we calculate the offset from the top of the document. This is done in a while loop, because the target anchor could be inside another element like a div or a table. After calculating the offset, we get a pointer to the HTML window and call the scrollTo function to make it scroll to the anchor position.

Now the only thing you need to do is to render your HTML using the method in my previous blog entry and then call this new ScrollToAnchor function with the name of the anchor to which you want to scroll.

The Windows Phone Application Platform was revealed at MIX 2010. If you couldn’t make it to Las Vegas to attend MIX, you can find the keynotes and sessions here. They explain in great details the Windows Phone 7 Series and how to develop applications for it.

The WP7S developer platform contains 2 frameworks:

• Silverlight: to make rich interactive applications
• XNA: to make complex 2D/3D games

Code is written in C#.

Everyone can start writing applications for the new phone platform. You only need to download 1 free package. This packages contains:

• Visual Studio 2010 Express for Windows Phone CTP
• Windows Phone Emulator CTP
• Silverlight for Windows Phone CTP
• XNA 4.0 Game Studio CTP

Download the package to get started. Only Windows Vista and Windows 7 are officially supported to run the tools. Note that the tools are currently in CTP state so they are not yet final. If you want to use Expression Blend you have to download it separately.

More information can be found on the Windows Phone 7 Series Developer Site, where you can also find developer guides, more detailed information, Windows Marketplace submission guidelines, forums, a few code samples etc…

Microsoft has a WebBrowser control that is actually an Internet Explorer control that you can use to display HTML in your own applications. More information about this WebBrowser control can be found on MSDN. By using this control it’s very easy to display online or offline webpages. However, it’s not immediately obvious how to make it display HTML that you might have in a memory buffer. Of course, one solution is to write the HTML to a temporary file and then load that file using the WebBrowser control, but obviously there is a better way for doing this which I will explain below.

The first thing you have to do is to add the WebBrowser control to your dialog. So, in Visual Studio, open the resource editor and then open the dialog onto which you want to put the WebBrowser control. Once the dialog is opened in the resource editor, right click on an empty space on the dialog and select “Insert ActiveX Control…”. This will open a new window in which you can select “Microsoft Web Browser” and then click OK. Visual Studio will automatically create a wrapper class for this ActiveX control which will probably be called explorer.h and explorer.cpp while the wrapper class will most likely be called CExplorer.

Now, right click the WebBrowser control on your dialog and select “Add Variable”. Make a variable with category set to “Control” and with the variable type set to the wrapper class “CExplorer” and hit OK.

Now we can start writing code. The first thing required is to load up some basic document; I use about:blank. Do this in your OnInitDialog handler as follows.

COleVariant loc(L"about:blank");
m_explorer.Navigate2(loc, NULL, NULL, NULL, NULL); 

The above is very important. If you don’t load an initial document, the WebBrowser control will not render any HTML that you try to push to it. This also means that before you can start writing HTML from memory in the WebBrowser control, you have to wait until the initial document has been fully loaded. This can be done with the “DocumentComplete” event. In the dialog editor, right the WebBrowser control and click on “Add Event Handler…”. Select “DocumentComplete” as message type, select the appropriate class and click “Add and Edit”. You can use that handler to change a boolean variable in your code to mark whether the document has been fully loaded. When it is fully loaded you can start writing HTML from memory to it.

Once that is finished, you can add the following helper function:

#include <MsHTML.h>
void CMyDlg::WriteHTML(const wchar_t* html)
{
	IDispatch* pHtmlDoc = m_explorer.get_Document();
	if (!pHtmlDoc)
		return;
	CComPtr<IHTMLDocument2> doc2;
	doc2.Attach((IHTMLDocument2*)pHtmlDoc);
	if (!doc2)
		return;
	 // Creates a new one-dimensional array
	SAFEARRAY* psaStrings = SafeArrayCreateVector(VT_VARIANT, 0, 1);
	if (!psaStrings)
		return;
	BSTR bstr = SysAllocString(html);
	if (bstr)
	{
		VARIANT* param;
		HRESULT hr = SafeArrayAccessData(psaStrings, (LPVOID*)&param);
		if (SUCCEEDED(hr))
		{
			param->vt = VT_BSTR;
			param->bstrVal = bstr;
			hr = SafeArrayUnaccessData(psaStrings);
			if (SUCCEEDED(hr))
			{
				doc2->write(psaStrings);
				doc2->close();
			}
		}
	}
	// SafeArrayDestroy calls SysFreeString for each BSTR!
	if (psaStrings)
		SafeArrayDestroy(psaStrings);
}

With the above function, it’s very easy to dynamically create and display HTML from memory. For example:

WriteHTML(L"<html><body><h1>My Header</h1><p>Some text below the header</p></body></html>");

Note that the above code is expecting a Unicode build. If you don’t use Unicode, you need to change the wchar_t types and you need to change the way how you allocate the BSTR variable.

That’s it. Pretty easy if you know how to do it, but it took me some time to figure it out.

[ Update: Fixed some typos and added mshtml.h reference. ]

[ Update 2: Added a call to "doc2->close();" after "doc2->write()" and added code to check the result of the doc2.Attach() call. ]

The Release Candidate of Visual Studio 2010 has changed the behaviour of RValue references slightly compared to the implementation in the Visual Studio 2010 beta versions. This is because the C++0x standard commitee has changed the RValue reference feature a bit and Visual Studio 2010 RC has incorporated those standard changes. Unfortunately, this might lead to compiler errors when you try to build code that is following the old standard. Let me give an example. Previously using a beta version of Visual Studio 2010 that was using the old C++0x standard, the following code would compile without any problems.

#include <iostream>
using namespace std;

// Increment value by 1 using RValue reference parameter.
int increment(int&& value)
{
   cout << "value = " << value << endl;
   value++;
   return value;
}

int main()
{
   int a = 10;
   int b = 20;

   // Increment a
   int result = increment(a);
   cout << "  a=" << a << ", b=" << b << ", result=" << result << endl;
   // Increment b
   result = increment(b);
   cout << "  a=" << a << ", b=" << b << ", result=" << result << endl;
   // Increment an expression
   result = increment(a + b);
   cout << "  a=" << a << ", b=" << b << ", result=" << result << endl;
   // Increment a literal
   result = increment(3);
   cout << "  a=" << a << ", b=" << b << ", result=" << result << endl;

   return 0;
} 

However, when trying to compile this using the latest release candidate of Visual Studio 2010, you will get the following errors:

rvalue_test.cpp(18): error C2664: 'increment' : cannot convert parameter 1 from 'int' to 'int &&'
          You cannot bind an lvalue to an rvalue reference
rvalue_test.cpp(21): error C2664: 'increment' : cannot convert parameter 1 from 'int' to 'int &&'
          You cannot bind an lvalue to an rvalue reference

These are related to the lines that are trying to increment a and b. Incrementing an expression or a literal still works as before. To get rid of those errors, you need to convert the lvalue to an rvalue. You can use the std::move function for this as shown in red below.

#include <iostream>
using namespace std;

// Increment value by 1 using RValue reference parameter.
int increment(int&& value)
{
   cout << "value = " << value << endl;
   value++;
   return value;
}

int main()
{
   int a = 10;
   int b = 20;

   // Increment a
   int result = increment(std::move(a));
   cout << "  a=" << a << ", b=" << b << ", result=" << result << endl;
   // Increment b
   result = increment(std::move(b));
   cout << "  a=" << a << ", b=" << b << ", result=" << result << endl;
   // Increment an expression
   result = increment(a + b);
   cout << "  a=" << a << ", b=" << b << ", result=" << result << endl;
   // Increment a literal
   result = increment(3);
   cout << "  a=" << a << ", b=" << b << ", result=" << result << endl;

   return 0;
}

This now compiles without any errors and produces the following output:

value = 10
  a=11, b=20, result=11
value = 20
  a=11, b=21, result=21
value = 32
  a=11, b=21, result=33
value = 3
  a=11, b=21, result=4

Now, it again works as expected

Microsoft has released the Release Candidate version of Visual Studio 2010 and the .NET Framework 4.

See Scott Guthrie blog post about it.

Right now it’s available for MSDN subscribers.
On Wednesday 10th of February everyone will be able to get their hands on it

Two important things to know (from Scott Guthrie blog post):

• If you have previously installed VS 2010 Beta 2 on your computer you should use Add/Remove Programs (within Windows Control Panel) to remove VS 2010 Beta2 and .NET 4 Beta2 before installing the VS 2010 RC.  Note that VS 2010 RC can be installed on the same machine side-by-side with VS 2008 and VS 2005.
• Silverlight 3 projects are supported with today’s VS 2010 RC build – however Silverlight 4 projects are not yet supported.  We will be adding VS 2010 RC support for SL4 with the next public Silverlight 4 drop. If you are doing active Silverlight 4 development today we recommend staying with the VS10 Beta 2 build for now.

Visual Studio 2010 and .NET Framework 4 Beta 2 are now available. The final version is scheduled for 22nd of March 2010. I’m looking forward to it

For Visual C++ developers there are lots of new things to look forward to, like parallel programming, MFC ribbon resource editor, easy application local deployment model etc etc…

When you use the .NET Framework you will apparently be able to have deployments with up to 81% reduction in the framework size by using the Client Profile.

According to the press release:

“The company also outlined a simplified product lineup and pricing options for Visual Studio 2010 as well as new benefits for MSDN subscribers, including the Ultimate Offer, available to all active MSDN Premium subscribers at the official product launch on March 22, 2010.”

The product lineup is simplified with the following versions:

• Microsoft Visual Studio 2010 Ultimate with MSDN. The comprehensive suite of application life-cycle management tools for software teams to help ensure quality results from design to deployment
• Microsoft Visual Studio 2010 Premium with MSDN. A complete toolset to help developers deliver scalable, high-quality applications
• Microsoft Visual Studio 2010 Professional with MSDN. The essential tool for basic development tasks to assist developers in implementing their ideas easily

Download Beta 2 now.

Read the full Microsoft press release.

I just stumbled upon the Windows API Code Pack for the Microsoft .NET Framework. It’s a code pack that allows .NET developers to take advantage of some of the new Windows 7 features.

Features supported by version 0.9 of the code pack are:

• Windows 7 Taskbar Jump Lists, Icon Overlay, Progress Bar, Tabbed Thumbnails, and Thumbnail Toolbars.
• Known Folders, Windows 7 Libraries, non-file system containers, and a hierarchy of Shell Namespace entities.
• Windows 7 Explorer Browser Control.
• Shell property system.
• Windows Vista and Windows 7 Common File Dialogs, including custom controls.
• Windows Vista and Windows 7 Task Dialogs.
• Direct3D 11.0, Direct3D 10.1/10.0, DXGI 1.0/1.1, Direct2D 1.0, DirectWrite, Windows Imaging Component (WIC) APIs. (DirectWrite and WIC have partial support)
• Sensor Platform APIs
• Extended Linguistic Services APIs
• Power Management APIs
• Application Restart and Recovery APIs
• Network List Manager APIs
• Command Link control and System defined Shell icons.

Requirements:

• .NET Framework 3.5 or later.
• This library targets the Windows 7 RC version, though some of the features will work on the older versions of Windows operating system.
• DirectX features have dependency on Windows SDK for Windows 7 RC and March 2009 release of DirectX SDK.

There are also a few short 2-minute videos available to show you how easy it is to use some of the above features.

Visual C++ 2010 comes with a brand new library called the Parallel Pattern Library or PPL. It is a powerful library that makes writing parallel code easier which is getting more and more important with the current and upcoming multicore CPUs. This article will give an overview of the PPL. Read the rest of this entry »

Windows Vista introduced the restart manager. It is used to automatically restart an application after it crashes. It can also be used to restart application after a reboot by a Windows Installer or update. If you create a new MFC application using the project wizard in Visual C++ 2010, you will automatically get support for the restart manager. If you want to add support to an existing MFC application, you only need to add 1 line of code to the constructor of your CWinApp or CWinAppEx derived class. Read the rest of this entry »

Windows Vista introduced the concept of Task Dialogs. Those are a powerful replacement for the standard message boxes. Read the rest of this entry »

The SafeInt library is a new addition to Visual C++ 2010. It allows you to safely perform arithmetic operations on integers ranging from 8-bit to 64-bit. The SafeInt library will automatically detect arithmetic overflow or divide by zero. Using the SafeInt library is pretty easy. The following piece of code uses the SafeInt library to safely calculate the addition of two 8-bit integers. Read the rest of this entry »

Starting with Visual C++ 2010, the ‘auto’ keyword has a different meaning. Auto is now used as a variable type and it instructs the compiler to figure out the exact type itself. This makes it much easier to define function pointers or to iterate over vectors for example. This post will give a brief overview of how to use the ‘auto’ keyword. Read the rest of this entry »

A new feature in Visual C++ 2010 is called Rvalue References. This is a feature from the C++0x standard. One thing that Rvalue References can be used for is to implement move semantics for objects. To add move semantics to a class, we need to implement a move constructor and a move assignment operator (optional). This article will briefly explain the benefits of move constructors and how to write them. Read the rest of this entry »