Posts Tagged ‘Samples’

Using .NET Classes/Modules from native C++

September 17th, 2009 No comments

The goal of this article is to describe a more or less generic way to access .NET managed object from a native C++ application.


The goal of this article is to describe a more or less generic way to access .NET managed object from a native C++ application. I will present a dynamic link library (dll) which can be used, for example, to augment legacy C++ applications with the power of managed code. The library is written in C++/CLI which is the only .NET language which can be used to accomplish such a task.
All code was written with Visual C++ 2008, it’s also possible to do this with previous versions of the Microsoft C++ compilers, but Microsoft has done a lot of changes to C++/CLI for VS 2008, so it’s now much easier to use than in older version.
The “more” generic in the first sentence means that the library can be used to call any function (with an unlimited amount of parameters) of any managed class. The “less” means that the parameter types are limited to the native C++ types and a few user defined types (string, date/time, …). It’s easy to provide support for your own types, but therefore the code for the dll has to be extended by yourself.


Windows 7 Goodies in C++: Taskbar Progress and Status Indicators

September 16th, 2009 No comments

An intro to using Taskbar progress bars and overlay icons with your Windows 7 applications


One of the major changes to how the Windows 7 Taskbar operates is in an area that Microsoft calls peripheral status. This covers two types of status indicators: progress for long operations, and icons for important notifications. Apps can continue to use progress dialogs during long operations, but the Windows 7 Taskbar lets the app show a progress bar in its Taskbar button as well, so the user can see the progress indicator at a glance, without having to switch to the app.

Many apps also use the notification area to convey important status information. For example, Outlook shows an icon when you have new email. However, in Windows 7, notification area icons are hidden by default, so the notification area is no longer useful for displaying this kind of status. The Taskbar lets an app display a 16×16 icon that is overlaid on the existing icon in its Taskbar button. This prevents the notification area from getting too crowded, and keeps the status icon visually associated with the app that created it.

This article’s sample app is a re-write of the file downloader from my article Using Internet Explorer to download files for you. The app shows the download progress in its Taskbar button, in addition to a traditional progress bar in the dialog. This app didn’t have a notification area icon before, but for the purposes of demonstrating the API calls involved, it has commands for showing a status icon as well.

The sample code for this article was built with Visual Studio 2008, WTL 8.0, and the Windows 7 RC SDK.


Tags: , , , ,