防止NSURLSession缓存响应

Question

为什么它会缓存响应.它返回先前获取的响应.它甚至可以在关闭网络连接时工作.重置iOS模拟器似乎也不起作用.提出请求,然后再次使用Internet脱机工作(缓存).

public let urlSession: NSURLSession

public init()
{
    // ...

    var configuration = NSURLSessionConfiguration.defaultSessionConfiguration()
    configuration.requestCachePolicy = NSURLRequestCachePolicy.ReloadIgnoringLocalCacheData
    urlSession = NSURLSession(configuration: configuration)
}

func makeRequest(path: String, httpMethod:String, body:String?, baseUrl: String?, headers:[String:String]=[:], callback: JsonRequestCallback)
{
    let urlString = (baseUrl ?? customOAuth2Manager.API_URL) + path
    let url = NSURL(string: urlString)
    let request = oauthInstance.request(forURL: url!)

    request.HTTPMethod = httpMethod
    self.customOAuth2Manager.setupRequest(request)

    for (key, value) in headers {
        request.setValue(value, forHTTPHeaderField:key)
    }

    if let body = body where body != "" {
        let postData = (body as NSString).dataUsingEncoding(NSUTF8StringEncoding)
        request.HTTPBody = postData
    }

    let task = urlSession.dataTaskWithRequest(request) { data, response, error in
        self.parseData(data, response:response, error:error, body:body, callback: callback)
    }
    task.resume()
}

更新

我设法通过调用该代码来解决它didFinishLaunching在AppDelegate:

func removeUrlCache()
{
    NSURLCache.setSharedURLCache(NSURLCache(memoryCapacity: 0, diskCapacity: 0, diskPath: nil))
}

但是,我仍然很好奇为什么我的原始代码不起作用.为所有应用程序禁用缓存以解决我的问题也感觉有点难看.

Answer 1

谢谢你的提问.它让我走上了正确的道路.

有更多的可能性,NSURLCache.sharedURLCache()您不需要为此更改内存容量和磁盘容量.

您可以删除所有缓存的响应.适合我.

URLCache.shared.removeAllCachedResponses()

或者,您可以删除单个响应的缓存.不适用于iOS 9.

let request = URLRequest(url: URL(string: url)!, cachePolicy: .reloadIgnoringLocalCacheData, timeoutInterval: 10)
    URLCache.shared.removeCachedResponse(for: request)

//Do your request here

我希望它可以帮助别人!

编辑: NSURLCache.sharedURLCache().removeCachedResponseForRequest(request)不幸的是不适合我

我的替代方案是:我正在使用它来进行刷新,我正在跟踪上次更新日期.所以我使用以下代码:

 URLCache.shared.removeCachedResponses(since: lateUpdate)

但由于某种原因,这不是以太工作.

从iOS 8开始,单缓存删除方法似乎被打破:https://stackoverflow.com/a/26343653/2826164

Answer 2

不确定这是否真的会阻止chaching或者每次都强制重新加载,但这对我有用:

request.cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringCacheData

这是一个截图,显示其他选项,以防有人可能需要它们: