在登錄的接口每次服務(wù)器都會(huì)默認(rèn)給客戶端發(fā)送一個(gè)cookie,在退出登錄的時(shí)候可以
NSHTTPCookieStorage *cookieJar = [NSHTTPCookieStorage sharedHTTPCookieStorage];
NSArray *_tmpArray = [NSArray arrayWithArray:[cookieJar cookies]];
for (id obj in _tmpArray) {
[cookieJar deleteCookie:obj];
}