All of a sudden, my intellisense window in VS2010 Express has a input field which has exactly what I'm typing. This wouldn't bother me, except that now space doesn't commit the selected choice that intellisense gives me.
Also note that the option in Tools-Options-Text Editor-C#-IntelliSense does have the "Comitted by pressing the spacebar" checked, yet it doesn't work.
Looks like you've messed with completion mode at some point. This can be changed by going to Edit -> IntelliSense -> Toggle Completion Mode or by just hitting Ctrl + Alt + Space
Microsoft finally fixed it.
It looks like the state of completion mode (toggled by Ctrl-Alt-Space) is finally persisted and applied to new windows.
Set it the way you like it. Close and reopen. Start new windows. It should stick to all of them.
Version: SP1 for Microsoft SQL Server Management Studio 2014
来源：https://stackoverflow.com/questions/5718657/intellisense-window-has-input-field-and-doesnt-commit-on-space