June 2011 | The Old New Thing

2011 mid-year link clearance

Raymond ChenJune 30, 2011Jun 30, 201106/30/11

Another round of the semi-annual link clearance. And, as always, the obligatory plug for my column in TechNet Magazine:

The UseUrl attribute in the App Paths key indicates that your application can accept a URL on the command line

Raymond ChenJune 30, 2011Jun 30, 201106/30/11

Setting the UseUrl attribute in your App Paths key indicates that your application can accept a URL on the command line as the document to be opened. The documentation for this attribute is a confusing blend of raw documentation, guidance, history, and an example. Let's tease the parts apart so you won't confuse the example with the contract.

What happens to WPARAM, LPARAM, and LRESULT when they travel between 32-bit and 64-bit windows?

Raymond ChenJune 29, 2011Jun 29, 201106/29/11

The integral types WPARAM, LPARAM, and LRESULT are 32 bits wide on 32-bit systems and 64 bits wide on 64-bit systems. What happens when a 32-bit process sends a message to a 64-bit window or vice versa? There's really only one choice when converting a 64-bit value to a 32-bit value: Truncation. When a 64-bit process sends a message to a 32-

A different way to win from one of those claw game

Raymond ChenJune 28, 2011Jun 28, 201106/28/11

I know two people (siblings) who are experts at those claw games. They can look at a claw game, assess the situation, decide whether there is a winnable toy, and if so, drop in their quarter and grab it. I asked the elder sibling how they arrived at this amazing skill. "As a teenager, I spent something like $20 pumping quarters into one of th

How do I display the Find Printers dialog programmatically?

Raymond ChenJune 28, 2011Jun 28, 201106/28/11

A customer wanted to display the Find Printers dialog programmatically to let the user pick a printer from Active Directory and wanted to know whether this was possible. Yes, it's possible, and there's more than one way to do it. There's the lazy way and the overachieving way. The overachieving way is to use the ICommonQuery::Open

There's more to workflow than hitting F5 in the IDE

Raymond ChenJune 27, 2011Jun 27, 201106/27/11

Commenter Stu suggested that instead of having code to auto-correct dialog templates, why not have a program that corrects them at build time? That way, Windows wouldn't have to make all these accommodations for programs that didn't understand the new dialog template requirements for property sheet pages. For one thing, this model assumes th

Why doesn't my MessageBox wrap at the right location?

Raymond ChenJune 24, 2011Jun 24, 201106/24/11

A customer reported that the MessageBox function was wrapping text "at the wrong location." Our program displays a message with the MessageBox function, and we use the '\n' character to force line breaks at positions we choose. But we've found that starting in Windows Vista, the line breaks we placed are not working. The MessageBox funct

What happens when applications try to copy text by sending Ctrl+C

Raymond ChenJune 23, 2011Jun 23, 201106/23/11

I'm stealing this story from one of my colleagues. I remember one app from a long time ago that had a feature where you could hit a global short cut key (or something like that) to launch the dictionary. It was also smart in that it would detect the current selected text and immediately search the dictionary for that term. One day I was ru

How do I compress files (via NTFS compression) from the command line?

Raymond ChenJune 22, 2011Jun 22, 201106/22/11

A customer wanted to know whether there was a way to compress files and directories (in the sense of NTFS compression) from a script or from the command line. They knew about the Properties dialog, but they wanted something scriptable. The command-line tool for this is COMPACT.EXE. Type compact /? for usage information. The customer liaison

How to get Windows Media Player to single-step a video

Raymond ChenJune 21, 2011Jun 21, 201106/21/11

I always forget how to do this, so I'm going to write it down so I can look it up later. When a video is playing, right-click the volume control slider and select Enhancements, then Play speed settings. (Actually, it also works if you right-click the speaker icon, the Stop button, the Replay button, or the Shuffle button, but the volume contr

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