SendInput() misinterpreted in certain applications

Question

My c# project sends an injected key combo to the foreground window. In notepad, Firefox, IE9 everything works as it should, but Adobe Illustrator CS5 seems to misinterpret the sent combos: for example CTRL+G becomes CTRL+SHIFT+WHEEL_DOWN so instead of grouping selected objects it scrolls the page to the left. (A low level keyboard hook also confirmed that I'm sending the right combo.)

A quick test showed that there is method in this madness, so CTRL+F appears as CTRL+SHIFT+WHEEL_UP.

The system is Windows 7 64bit so at first I suspected some 32 vs 64 bit woe but things work properly in both 32 and 64 bit IE9.

Answer 1

I can't say for sure, but it sounds an awful lot like an issue that a user of my app pointed out (which is how I ended up here, searching for clues!).

For my app, it turned out that I needed to put some delay between the Control keydown event and the C (for copy, in this example) keydown. When sent at the same time as a single combination, results were very unpredictable.

http://www.strokesplus.com/forum/topic.asp?whichpage=1&TOPIC_ID=477#1024