HideCaret(0); {use 0 to let windows find which window
owns the caret, then hide it. Otherwise, you can directly
tell the HWND of the window that owns the caret, :}
Hehe, 不过我试了以下, 当您Click, 或者用Tab键激活它时,
TMemo却又把它显示出来了,
所以要在MouseDown, KeyUp放上这样的调用, (Not KeyDown)
And do not set the TabOrder of the Memo to be first ordered, that's
OK!