iOS webview 清除缓存

使用iOS的UIWebview会自动进行缓存，我们在开发的时候要记得清除Cookie和缓存。

_webView = nil;

[self cleanCacheAndCookie];

调用的方法代码如下：

/**清除缓存和cookie*/

- (void)cleanCacheAndCookie{

//清除cookies

NSHTTPCookie *cookie;

NSHTTPCookieStorage *storage = [NSHTTPCookieStorage sharedHTTPCookieStorage];

for (cookie in [storage cookies]){

[storage deleteCookie:cookie];

}

//清除UIWebView的缓存

NSURLCache * cache = [NSURLCache sharedURLCache];

[cache removeAllCachedResponses];

[cache setDiskCapacity:0];

[cache setMemoryCapacity:0];

}