February 2004 | The Old New Thing

The correct order for disabling and enabling windows

Raymond ChenFebruary 27, 2004Feb 27, 200402/27/04

If you want to display modal UI, you need to disable the owner and enable the modal child, and then reverse the procedure when the modal child is finished. And if you do it wrong, focus will get all messed up. If you are finished with a modal dialog, your temptation would be to clean up in the following order: But if you do that, ...

Why do timestamps change when I copy files to a floppy?

Raymond ChenFebruary 26, 2004Feb 26, 200402/26/04

Floppy disks use the FAT filesystem, as do DOS-based and Windows 95-based operating systems. On the other hand, Windows NT-based systems (Windows 2000, XP, 2003, ...) tend to use the NTFS filesystem. (Although you can format a drive as FAT on Windows NT-based systems, it is not the default option.) The NTFS and FAT filesystems store ...

Why can't I put hotlinks in notification icon balloon tips?

Raymond ChenFebruary 25, 2004Feb 25, 200402/25/04

The short answer: "Because there is no NIF_PARSELINKS flag." The long answer: When balloon tips were first developed, there was no ability to embed links. Consequently, programs were free to put insecure text in balloon tips, since there was no risk that they would become "live". So, for example, a virus scanner might say "The document 'XYZ...

What's so special about the desktop window?

Raymond ChenFebruary 24, 2004Feb 24, 200402/24/04

The window returned by GetDesktopWindow() is very special, and I see people abusing it all over the place. For example, many functions in the shell accept a window handle parameter to be used in case UI is needed. IShellFolder::EnumObjects, for example. What happens if you pass GetDesktopWindow()? If UI does indeed need to be ...

Invalid thread and process IDs

Raymond ChenFebruary 23, 2004Feb 23, 200402/23/04

Perhaps you want a value to use as a sentinel, which you want to be guaranteed is never a valid thread ID or process ID. What values can you use? Nothing is explicitly written about this topic, but you can put on your logic cap and figure it out. If you need an invalid thread ID, you can use zero. How do you know that zero is an ...

And we will build a processor with… ONE MILLION TRANSISTORS!

Raymond ChenFebruary 22, 2004Feb 22, 200402/22/04

A friend of mine decided to recaption this picture which is in the rotation on Intel's Hardware Design Home Page: Who knew that Dr. Evil designed CPUs, too...

Raymond's comment policy

Raymond ChenFebruary 21, 2004Feb 21, 200402/21/04

Okay, I was hoping it wasn't going to be needed but it takes only one bad apple... Here are the ground rules. Things that increase the likelihood that your comment will be edited or deleted: If a wave of comment spam is under way, I may choose to moderate or even close comments until the problem subsides. More rules may be added later...

Why do I get a QueryInterface(IID_IMarshal) and then nothing?

Raymond ChenFebruary 20, 2004Feb 20, 200402/20/04

A common problem when trying to get your new COM object off the ground is that you can't seem to be able to get it created. The object comes out of the class factory, and it gets a QueryInterface for IMarshal, and then nothing. What's going on? This is a sure sign that you didn't register your CLSID properly; most likely you forgot to ...

Sorry the posts are late lately

Raymond ChenFebruary 19, 2004Feb 19, 200402/19/04

Somehow the server is in a wonky state and my autopilot script that posts a new article at 7 every morning is getting error 500 back (internal server error). So I'm posting manually for the nonce. Expect erratic posting times until the problem is resolved...

No code is an island