Dev Blogs
Last time, we looked at the confusingly-named WM_UPDATEUISTATE and WM_CHANGEUISTATE messages. But how does the whole indicator thingie get off the ground? The default state for a window is to show all indicators. But as a special trick, the dialog manager will send a WM_UPDATEUISTATE message with UIS_INITIALIZE aft...
I always get confused by the and messages, and I have to go figure them out each time I need to mess with them. So this time, I'm going to write it down so I don't forget. Because the act of writing it down helps me to remember. It's like in school, where the teacher says, "This is a closed-book, closed-notes exam, but you are allowed to bring ...
What does GDI use and for? Nothing. The and are completely ignored by GDI when loading a bitmap. The values are there for the benefit of image-editing programs who want to record additional information about the bitmap, but GDI ignores them. Similarly, the and functions update a structure associated with each bitmap, but GDI does not...
Today's Little Program takes a rectangular portion of another application and continuously replicates it in its own client area. You might want to do this if you want to monitor a portion of an application like a custom progress bar, and the application doesn't use the Windows 7 taskbar progress indicator feature. (Maybe it's an old applicati...
The original question from the customer was why they couldn't get named file mappings to work at all, but it turns out that the reason is that they were using the full path to the file as the name, even though backslashes have special meaning in file mapping names. Okay, that problem can be solved by changing the backslash to some character lega...
More than once, I've seen somebody confused by how inline functions work. I have implemented a few inline functions in one of my cpp files, and I want to use it from other cpp files, so I declare them as extern. But sometimes I will get linker error 2019 (unresolved external) for the inline functions. // a.cpp inline bool foo() { return false...
When you ask a mathematician to come up with a formula to solve a problem, you will get something that looks pretty, but that doesn't mean that it lends itself well to computation. For example, consider the binomial coefficient, traditionally written nCk or C(n, k), and in more modern notation as ( nk ). If you ask a mathematician f...
Today's Little program shows how to read mouse input from a console program. You might use this if you are writing a console-mode text editor with mouse support, or maybe you want to want to add mouse support to your roguelike game. But I'm not going to implement the game itself. Instead, I'm just going to print mouse coordinates to the screen....
I'll assume that we all know what pidls are and how the shell namespace uses them. That's the prerequisite for today. A simple pidl is an item ID list that refers to a file or directory that may not actually exist. It's a way of playing "what if": "If there were a file or directory at this location, here is what I would have created to represent...
A customer using Visual Studio wanted to know how to obtain the current value of the x64 RSP register from a C/C++ function. They noted that on the x86, you can drop to inline assembly, and on the ia64, you can use the intrinsic to retrieve the value of any register. There is no corresponding intrinsic on x64. There's no really good way of doin...