iOS UIWebView清除缓存

//清除cookies
NSHTTPCookie *cookie;
NSHTTPCookieStorage *storage = [NSHTTPCookieStorage sharedHTTPCookieStorage];
for (cookie in [storage cookies]) 
{
    [storage deleteCookie:cookie];
}

//清除UIWebView的缓存
[[NSURLCache sharedURLCache] removeAllCachedResponses];

//清除缓存（全）
NSURLCache * cache = [NSURLCache sharedURLCache];  
[cache removeAllCachedResponses];  
[cache setDiskCapacity:0];  
[cache setMemoryCapacity:0];