ITfLanguageProfileNotifySink for Chinese sub-language change

Question

Simply put: why does the ITfLanguageProfileNotifySink interface sink not seem to invoke OnLanguageChange method when changing input language (from Language Bar) to one of the Chinese (Traditional), such as ChangJie or New Phonetic? This is on Windows 7. I get it going from say English to Chinese, but then when I select a different Chinese (sub-) language, there is no notification?!

Answer 1

Because you haven't changed the language, you've changed the active Input Method.

One can have multiple input methods for the same language. To track input methods, you'll have to use ITfActiveLanguageProfileNotifySink and figure out how to interpret the CLSIDs for the various input methods in the OnActivated function.