使用iOS的UIWebview會自動進行緩存，我們在開發的時候要記得清除Cookie和緩存。

_webView = nil;

[self cleanCacheAndCookie];

調用的方法代碼如下：

/**清除緩存和cookie*/

- (void)cleanCacheAndCookie{

//清除cookies

NSHTTPCookie *cookie;

NSHTTPCookieStorage *storage = [NSHTTPCookieStorage sharedHTTPCookieStorage];

for (cookie in [storage cookies]){

[storage deleteCookie:cookie];

}

//清除UIWebView的緩存

NSURLCache * cache = [NSURLCache sharedURLCache];

[cache removeAllCachedResponses];

[cache setDiskCapacity:0];

[cache setMemoryCapacity:0];

}

iOS webview 清除緩存