Showing tag results for Code

We saw last time a sample program that moved a circle around. Today I'll try to build the classic demo of animating a lot of objects in a list. This isn't the prettiest code, but I wanted to make as few changes as possible. Start with the Timer-Driven Animation, and make these changes to the Main­Window.h header file. struct Item { I...

Windows 7 provides a component known as the Windows Animation Manager, known to some people by its acronym WAM, pronounced "wham". There are some nice sample programs for WAM on MSDN, but for some reason, the authors of the samples decided to animate the three color components of a resultant color. Because apparently the authors of those ...

Suppose you have a function that is registered to be called the next time something gets updated, and suppose that the notification is a one-shot notification and needs to be re-armed each time you want to wait for the next notification. (For example, the Reg­Notify­Change­Key­Value function behaves this way.) Consider the followi...

Today's Little Program is a command line version of the Shared Folders MMC snap-in. Why? Because it illustrates the usage pattern for the Net­Xxx family of functions. (It's also a clone of the networking portion of the openfiles tool.) The Net­Xxx family of functions generally work like this: You pass in some parameters that describe ...

Consider this function: void ChangeConsoleColor(WORD wColor) { HANDLE h = GetStdHandle(STD_OUTPUT_HANDLE); if (h != INVALID_HANDLE_VALUE) { SetConsoleTextAttribute(h, wColor); CloseHandle(h); } } "When I call this function, it works the first time, but when I call it a second time, Get­Std­Handle returns a handle numerically ide...

The convention when working with device contexts is to restore them to the way you found them. If a drawing function selects a bitmap into a device context, then it should select the original bitmap into the device context before returning. Same for fonts, pens, all that stuff. But what if you decide to violate that convention? For example, maybe...

Today's Little Program creates a shortcut on the Start menu but marks it as "Do not put me on the front page upon installation." This is something you should do to any secondary shortcuts your installer creates. And while you're at it, you may as well set the "Don't highlight me as a newly-installed program" attribute used by Windows 7. (Reme...

Perhaps one of the most misunderstood sentences in the Win32 documentation is this little bit in the documentation for : If hFile is INVALID_HANDLE_VALUE, the calling process must also specify a size for the file mapping object in the dwMaximum­Size­High and dwMaximum­Size­Low parameters. In this scenario, Create­File­Map...

As a puzzle, commenter nobugz asks, "What kind of infinity is 1.#J?" double z = 0; printf("%.2f", 1/z); Now, the division by zero results in IEEE positive infinity, would would normally be printed as 1#INF. But the catch here is that the print format says "Display at most two places after the decimal point." But where is the decimal point in i...

The structure lets you specify a bitmap to appear next to the menu item. Is there a way to do this from a menu resource template? No. If you look at the format of menu templates, you'll see that there is nowhere to specify a bitmap. Which kind of makes sense, because it is the responsibility of the application to destroy the bitmap refer...