清除 UIWebview 缓存 [英] Clearing UIWebview cache

问题描述

我已经使用 UIWebview 使用 loadRequest: 方法加载网页，当我离开那个场景时，我调用 [self.webView stopLoading]; 并释放 webView.

I have used UIWebview to load a web page using loadRequest: method, when I leave that scene I call [self.webView stopLoading]; and release the webView.

在首次启动时的活动监视器中，我看到实际内存增加了 4MB，而在多次启动/加载时，实际内存没有增加.它只增加了一次.

In activity monitor on first launch i have seen that the real memory increased by 4MB, and on multiple launches/loading the real memory doesn't increase. It is increasing only once.

我已经检查了 webview 的保留计数.它是正确的，即 0.我认为 UIWebView 正在缓存一些数据.如何避免缓存或删除缓存数据?还是另有原因?

I have checked the retain count of webview. It is proper i.e., 0. I think UIWebView is caching some data. How do I avoid caching or remove cached data? Or is there another reason for this?

推荐答案

我实际上认为当您关闭 UIWebView 时它可能会保留缓存的信息.我尝试从我的 UIViewController 中删除一个 UIWebView，释放它，然后创建一个新的.当我返回某个地址时，新的可以准确记住我所在的位置，而无需重新加载所有内容(它会记住我之前的 UIWebView 已登录).

I actually think it may retain cached information when you close out the UIWebView. I've tried removing a UIWebView from my UIViewController, releasing it, then creating a new one. The new one remembered exactly where I was at when I went back to an address without having to reload everything (it remembered my previous UIWebView was logged in).

所以有几个建议:

[[NSURLCache sharedURLCache] removeCachedResponseForRequest:NSURLRequest];

这将删除特定请求的缓存响应.还有一个调用将删除在 UIWebView 上运行的所有请求的所有缓存响应:

This would remove a cached response for a specific request. There is also a call that will remove all cached responses for all requests ran on the UIWebView:

[[NSURLCache sharedURLCache] removeAllCachedResponses];

之后，您可以尝试删除任何与 UIWebView 相关联的 cookie:

After that, you can try deleting any associated cookies with the UIWebView:

for(NSHTTPCookie *cookie in [[NSHTTPCookieStorage sharedHTTPCookieStorage] cookies]) {

    if([[cookie domain] isEqualToString:someNSStringUrlDomain]) {

        [[NSHTTPCookieStorage sharedHTTPCookieStorage] deleteCookie:cookie];
    }
}

Swift 3:

// Remove all cache 
URLCache.shared.removeAllCachedResponses()

// Delete any associated cookies     
if let cookies = HTTPCookieStorage.shared.cookies {
    for cookie in cookies {
        HTTPCookieStorage.shared.deleteCookie(cookie)
    }
}

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