What reason can cause the IME language bar invisible in the task bar?

Question

I have a weird issue that the IME is invisible in the task bar when the focus is in a window. In original code, this window is not permitted to associate with IME and we call "ImmAssociateContext(m_hWnd, NULL)" in the WM_CREATE handler. Now there is new requirement that we need to permit the user use IME for this window. Then I remove the code "ImmAssociateContext(m_hWnd, NULL)". To my surprise, the IME is invisble in the task bar even I use the hot key to activate the IME, please refer the screenshot:

From the above screenshot, the IME is activated actually and the language bar is shown. But it is invisible in the task bar. The normal result should be:

I investigated this issue for a whole day, but found nothing. Now I have no idea what can cause this issue? Set some window property or else? Anybody can pls give some clues?

Appreciate!

Answer 1

我发现Windows具有可隐藏/显示语言栏的COM ITfLangBarMgr的原因。