The Old New Thing
Practical development throughout the evolution of Windows.
Latest posts
If you want to be notified when your app is uninstalled, you can do that from your uninstaller
A customer had a rather strange request. "Is there a way to be notified when the user uninstalls any program from Programs and Features (formerly known as Add and Remove Programs)?" They didn't explain what they wanted to do this for, and we immediately got suspicious. It sounds like the customer is trying to do something user-hostile, like seeing that a user uninstalled a program and immediately reinstalling it. (Sort of the reverse of force-uninstalling all your competitors.) The customer failed to take into account that there are many ways of uninstalling an application that do not involve navigating to the...
Did the Windows 95 interface have a code name?
Commenter kinokijuf wonders whether the Windows 95 interface had a code name. Nope. We called it "the new shell" while it was under preliminary development, and when it got enabled in the builds, we just called it "the shell." (Explorer originally was named Cabinet, unrelated to the container file format of the same name. This original name lingers in the window class: CabinetWClass.)
Finding the shortest path to the ground while avoiding obstacles
Today's Little Program solves the following problem: Consider a two-dimensional board, tall and narrow. Into the board are nailed a number of horizontal obstacles. Place a water faucet at the top of the board and turn it on. The water will dribble down, and when it hits an obstacle, some of the water will go left and some will go right. The goal is to find the shortest path to the ground from a given starting position, counting both horizontal and vertical distance traveled. ⬤ • • • • • • • • • • &bu...
How do I obtain the computer manufacturer's name from C++?
Some time ago, I gave a scripting solution to the problem of obtaining the computer manufacturer and model. But what if you want to do this from C++? I could translate the script into C++, or I could just point you to Creating a WMI Application Using C++ in MSDN. In particular, one of the WMI C++ Sample Applications does exactly what you want: Example: Creating a WMI Application. The only things you need to do are
When I send a WM_GETFONT message to a window, why don't I get a font?
A customer reported that the message was not working. Specifically, they sent the message to a window, and they can plainly see that the window is rendering with a particular font, yet the message returns 0. Why isn't the window returning the correct font handle? The and messages are not mandatory. A window may choose to support them, or it may choose not to, or it may even choose to support one but not the other. (Though if it supports , it probably ought to support .) For example, our scroll bar program creates a custom font for the items in the list, but it does not implement the or messages. If you t...
When will GetSystemWindowsDirectory return something different from GetWindowsDirectory?
Most of the time, the returns the Windows directory. However, as noted in the documentation for : With Terminal Services, the GetSystemWindowsDirectory function retrieves the path of the system Windows directory, while the GetWindowsDirectory function retrieves the path of a Windows directory that is private for each user. On a single-user system, GetSystemWindowsDirectory is the same as GetWindowsDirectory. What's going on here, and how do I test this scenario? When Terminal Services support was being added to Windows NT 4.0 in the mid 1990's, the Termi...
Microspeak: Tell Mode / Ask Mode
As a product nears release, the rate of change slows down, and along the way, the ship room goes through stages known as Tell Mode and Ask Mode. In Tell Mode, any changes to the product do not require prior approval, but you are required to present your changes to the next ship room meeting and be prepared to explain and defend them. The purpose of this exercise is to get teams accustomed to the idea of having to present their changes to the ship room as a warm-up for Ask Mode. There is also the psychological aspect: If you have to present and defend your changes, you are going to be more careful about deciding ...
The alternate story of the time one of my colleagues debugged a line-of-business application for a package delivery service
Some people objected to the length, the structure, the metaphors, the speculation, and fabrication. So let's say they were my editors. Here's what the article might have looked like, had I taken their recommendations. (Some recommendations were to text that was also recommended cut. I applied the recommendations before cutting; the cuts are in gray.) You tell me whether you like the original or the edited version.
How can I get the URL to the Web page the clipboard was copied from?
When you copy content from a Web page to the clipboard and then paste it into OneNote, OneNote pastes the content but also annotates it "Pasted from ...". How does OneNote know where the content was copied from? As noted in the documentation for the HTML clipboard format, Web browsers can provide an optional property to specify the Web page the HTML was copied from. Let's write a Little Program that mimics what OneNote does, but just in plain text, because I don't want to try to parse HTML. This is much easier to do in C#, because the BCL provides most of the helper functions. First, we get the text fro...