January 2011 | The Old New Thing

Solutions that require a time machine: Making applications which require compatibility behaviors crash so the developers will fix their bug before they ship

Raymond ChenJanuary 31, 2011Jan 31, 201101/31/11

A while ago, I mentioned that there are many applications that rely on WM_PAINT messages being delivered even if there is nothing to paint because they put business logic inside their WM_PAINT handler. As a result, Windows sends them dummy WM_PAINT messages. Jerry Pisk opines, Thanks to the Windows team going out of their way not to break ...

Some remarks on VirtualAlloc and MEM_LARGE_PAGES

Raymond ChenJanuary 28, 2011Jan 28, 201101/28/11

If you try to run the sample program demonstrating how to create a file mapping using large pages, you'll probably run into the error ERROR_NOT_ALL_ASSIGNED (Not all privileges or groups referenced are assigned to the caller) when calling AdjustTokenPrivileges. What is going on? The AdjustTokenPrivileges enables ...

How do you obtain the icon for a shortcut without the shortcut overlay?

Raymond ChenJanuary 27, 2011Jan 27, 201101/27/11

The easy one-stop-shopping way to get the icon for a file is to use the SHGetFileInfo function with the SHGFI_ICON flag. One quirk of the SHGetFileInfo function is that if you pass the path to a shortcut file, it will always place the shortcut overlay on the icon, regardless of whether you passed the SHGFI_ADDOVERLAYS...

Microspeak: Leverage

Raymond ChenJanuary 26, 2011Jan 26, 201101/26/11

At Microsoft, leverage is not a term of physics whereby a force can be magnified by the application of mechanical advantage. It is also not a term of finance whereby the power of a small amount of money can be magnified by the assumption of debt. In fact, at Microsoft, the word leverage isn't even a noun. It is a verb: to leverage, leverages, ...

Why does the name of my TEMP directory keep changing?

Raymond ChenJanuary 25, 2011Jan 25, 201101/25/11

A customer liaison contacted the shell team with the following request: Subject: Support case: 069314718055994 On two of my customer's machines, he's finding that if he opens %TEMP% from the Start menu, it opens C:\Users\username\AppData\Local\Temp\1, C:\Users\username\AppData\Local\Temp\2, and so on. Each time the user logs off and back on...

There's a default implementation for WM_SETREDRAW, but you might be able to do better

Raymond ChenJanuary 24, 2011Jan 24, 201101/24/11

If your window doesn't have a handler for the WM_SETREDRAW message, then DefWindowProc will give you a default implementation which suppresses WM_PAINT messages for your window when redraw is disabled, and re-enables WM_PAINT (and triggers a full repaint) when redraw is re-enabled. (This is internally accomplished by making the...

The 2011/2012 Seattle Symphony subscription season at a glance

Raymond ChenJanuary 21, 2011Jan 21, 201101/21/11

Every year, I put together a little pocket guide to the Seattle Symphony subscription season for my symphony friends to help them decide which ticket package they want. As before, you might find it helpful, you might not, but either way, you're going to have to suffer through it. Here's the at-a-glance season guide for the first season ...

Modality, part 9: Setting the correct owner for modal UI, practical exam

Raymond ChenJanuary 21, 2011Jan 21, 201101/21/11

Here's a question that came from a customer. You can answer it yourself based on what you know about modal UI. (If you're kind of rusty on the topic, you can catch up here.) I've left in some irrelevant details just to make things interesting. Our program launches a helper program to display an Aero Wizard to guide the user through ...

How to turn off the exception handler that COM "helpfully" wraps around your server

Raymond ChenJanuary 20, 2011Jan 20, 201101/20/11

Historically, COM placed a giant try/except around your server's methods. If your server encountered what would normally be an unhandled exception, the giant try/except would catch it and turn it into the error RPC_E_SERVERFAULT. It then marked the exception as handled, so that the server remained running, thereby "improving robustness by ...

Why didn't they use the Space Shuttle to rescue the Apollo 13 astronauts?

Raymond ChenJanuary 19, 2011Jan 19, 201101/19/11

Many decisions make sense only in the context of history. Much like the moviegoers who were puzzled why NASA didn't just use the Space Shuttle to rescue the Apollo 13 astronauts, computer users of today, when looking back on historical decisions, often make assumptions based on technology that didn't exist. Consider, for example, pointing ...

The Old New Thing