vim folding settings

At first, I can't open foldings in a file as when it closed even after adding the two code as follow:
au BufWinLeave * mkview
au BufWinEnter * silent loadview
I guessed the settings must be recorded somewhere. Then I found there was a flash red before I closed a file but I couldn't get it clearly. I use the command "mkview" by accident. Thus found the hint:can't get into dir "~/.vim/view..." & there did wasn't the dir. After a mkdir of it I can record a file's folding information.