The localStorage questions about webApp

I made a ios shell embedded a webview, is actually pointing to a website.
Now question is, html5 localStorage after the exit will clear the app, so some features disabled.
If I open the site with sarafi either quit the browser or restart the iPhone has been able to save.

Ask whether there are heroes engaged in related development it? Is not webApp unable to save localStorage?
Reply:
localStorage is a persistent local storage, unless you are automatically deleted,
Otherwise, there has been aAs you said, exiting on the failure should be sessionStorage, answer-level storage
Reply:
You say these words I know, because I have observed and theoretical differences only come to ask.
I'm not using sessionStorage.
Reply:
I was not clear enough to explain it?
What I mean is: When the browser opens the website, localStorage normal. When using the app embedded webview open the site, localStorage on the failure (each app before exiting into the app, the value of which has localStorage has prompted empty.)
Reply:
Inside the iPhone, open the Settings, Safari, there is what is what private data, open the try
Not how to get through the web app, you can try
Reply:
Okay, I'll try, thank you for your help!
Reply:
Landlord, I have encountered this problem solved?