November 2010 | The Old New Thing

Microspeak: Take-away

Raymond ChenNovember 30, 2010Nov 30, 201011/30/10

At Microsoft, the take-away is the essential message of a presentation or the conclusion that you are expected to draw from a situation. It is something you are expected to remember when the whole thing is over, a piece of information you take away with you as you leave the room. XYZ demo take away (title of a document) The preferred ...

What were Get/SetMessageExtraInfo ever used for?

Raymond ChenNovember 29, 2010Nov 29, 201011/29/10

KJK::Hyperion asks, "Could you shed some light on Get/SetMessageExtraInfo? It's almost like nobody on earth used them, ever, and I can't get some sample code." Yup, that's about right. Nobody on earth (to within experimental error) ever used them. These functions were introduced on July 20, 1990 (I'm looking at the change history right now) ...

Watching the game of Telephone play out in five seconds

Raymond ChenNovember 26, 2010Nov 26, 201011/26/10

Some time ago, I spent the Thanksgiving holiday with my nieces (ages 3 and 5 at the time), and I overheard this conversation between them. "Thanksgiving is over." — Christmas is coming! "It's Christmas time!" — Today is Christmas...

The easy way out is to just answer the question: What is the current Explorer window looking at?

Raymond ChenNovember 26, 2010Nov 26, 201011/26/10

A customer had the following question: We have an application which copies and pastes files. Our problem is that we want to paste the files into the folder which corresponds to the currently active Windows Explorer window. Right now, we're using SendKeys.SendWait("^(v)"), but we find this method unsatisfactory because we want to replace ...

What if two programs did this? Practical exam

Raymond ChenNovember 25, 2010Nov 25, 201011/25/10

A customer who doesn't read this blog had the following question: The requirement for our application is that it must be on top of all other windows, even in the presence of other windows with the topmost style. In our WM_KILLFOCUS and WM_PAINT messages, we set ourselves to topmost, and then call SetWindowPos to bring ourselves to the front...

You can filter the Common File dialog with wildcards

Raymond ChenNovember 24, 2010Nov 24, 201011/24/10

A customer reported an apparent inconsistency in the shell common file dialogs: The question mark appears to be treated differently from other invalid file name characters. I tried to save a file in Paint under the name ?.jpg but instead of telling me that I had an invalid character in the file name (as it does with other characters like / &...

But who's going to set up their own email server?

Raymond ChenNovember 23, 2010Nov 23, 201011/23/10

Many many years ago, back in the days when Microsoft's email address had exclamation points, an internal tool was developed to permit Microsoft employees to view and update their Benefits information from the comfort of their very own offices. Welcome to the paperless office! One of my friends noticed an odd sentence in the instructions for ...

Consequences of using variables declared __declspec(thread)

Raymond ChenNovember 22, 2010Nov 22, 201011/22/10

As a prerequisite, I am going to assume that you understand how TLS works, and in particular how __declspec(thread) variables work. There's a quite thorough treatise on the subject by Ken Johnson (better known as Skywing), who comments quite frequently on this site. The series starts here and continues for a total of 8 installments, ending ...

What's the difference between the Windows directory and the System directory?

Raymond ChenNovember 19, 2010Nov 19, 201011/19/10

(Windows was released on November 20, 1985, twenty-five years ago tomorrow. Happy birthday!) You have GetWindowsDirectory and you have GetSystemDirectory. Why do we need both? They're both read-only directories. They are both searched by LoadLibrary. They seem to be redundant. (There are other directories like GetWindowsSystemDirectory which ...

One possible reason why ShellExecute returns SE_ERR_ACCESSDENIED and ShellExecuteEx returns ERROR_ACCESS_DENIED

Raymond ChenNovember 18, 2010Nov 18, 201011/18/10

(The strangely-phrased subject line is for search engine optimization.) A customer reported that when they called ShellExecute, the function sometimes fails with SE_ERR_ACCESSDENIED, depending on what they are trying to execute. (If they had tried ShellExecuteEx they would have gotten the error ERROR_ACCESS_DENIED.) After a good amount of ...

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