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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...

Mini-me.

Many years ago, I wrote, "Do not write in-process shell extensions in managed code." Since I originally wrote that article, version 4 of the .NET Framework was released, and one of the features of that version is that it supports in-process side-by-side runtimes. Does that mean that it's now okay to write shell extensions in managed code? The ans...

When you associate a file handle with an I/O completion port with the function, you can pass an arbitrary pointer-sized integer called the which will be returned by the function for every I/O that completes against that file handle. But isn't that parameter superfluous? If somebody wanted to associated additional data with a file handle, they...