The Old New Thing

December 2010 - Page 2 of 4 - The Old New Thing

How do I simulate input without SendInput?

December 21, 2010 Dec 21, 2010 12/21/10
Raymond Chen
Michal Zygmunt wants to create a system where multiple applications can have focus, with different users generating input and directing them at their target applications. Attempting to simulate this by posting input messages didn't work. "Can you tell us maybe how SendInput is internally implemented so that we can use it to simulate only ...

Developing the method for taking advantage of the fact that the OVERLAPPED associated with asynchronous I/O is passed by address

December 20, 2010 Dec 20, 2010 12/20/10
Raymond Chen
You can take advantage of the fact that the associated with asynchronous I/O is passed by address, but there was some confusion about how this technique could "work" when kernel mode has no idea that you are playing this trick. Whether kernel mode is in on the trick is immaterial since it is not part of the trick. Let's start with a ...

What happened to the return code from WinMain in 16-bit Windows?

December 20, 2010 Dec 20, 2010 12/20/10
Raymond Chen
Commenter S asks, "What happened to the return code from WinMain in a Windows 3.1 app?" After all, there was no function in 16-bit Windows. Basically, the exit code vanished into the ether. Unless you captured it. The Toolhelp library provided a low-level hook into various parts of the kernel, allowing you to monitor, among other things, ...

The OVERLAPPED associated with asynchronous I/O is passed by address, and you can take advantage of that

December 17, 2010 Dec 17, 2010 12/17/10
Raymond Chen
When you issue asynchronous I/O, the completion function or the I/O completion port receives, among other things, a pointer to the structure that the I/O was originally issued against. And that is your key to golden riches. If you need to associate information with the I/O operation, there's no obvious place to put it, so some people end ...

Why does SHCOLUMNINFO have unusually tight packing?

December 16, 2010 Dec 16, 2010 12/16/10
Raymond Chen
Alternate title: News flash: Sometimes things happen by mistake rbirkby asks why the structure has 1-byte packing. "Was the expectation that there would be so many columns in a details view that the saving would be worthwhile?" Hardly anything that clever or ingenious. It's just the consequence of a mistake. When the structure was ...

There is no interface for preventing your notification icon from being hidden

December 15, 2010 Dec 15, 2010 12/15/10
Raymond Chen
Yes, it's another installment of I bet somebody got a really nice bonus for that feature. A customer had this question for the Windows 7 team: Our program creates a notification icon, and we found that on Windows 7 it is hidden. It appears properly on all previous versions of Windows. What is the API to make our icon visible? ...

The subtleties of a Will Ferrell movie, and other observations from the in-flight entertainment on a Chinese airline

December 14, 2010 Dec 14, 2010 12/14/10
Raymond Chen
My flights to and from Beijing were on Hainan Airlines, a Chinese airline. One consequence of this is that Mandarin Chinese is the primary language of communication; English is a distant second. It also means that the in-flight movies are subtitled in Chinese, so if you can't read Chinese, you are restricted to movies in languages you ...

Microspeak: Informing a product

December 14, 2010 Dec 14, 2010 12/14/10
Raymond Chen
Microspeak is not always about changing a word from a verb to a noun or changing a noun to a verb or even changing a noun into a verb and then back into a noun. Sometimes it's about data compression. This testing won't inform RC, but we'll need it to inform an RTM release. First, you need to familiarize yourself with a less-used sense of...

Some notes on my trip to Beijing disguised as travel tips

December 10, 2010 Dec 10, 2010 12/10/10
Raymond Chen
Single-use tickets purchased from subway vending machines are valid only on the day of purchase for use in that station. Do not buy your return ticket at the same time as your outbound ticket because it will not work. This detail is clearly explained on the ticket that you receive after you have paid for it. (Also, the vending machine will ask...