iOS缓存策略 [英] iOS Cache Policy

问题描述

我正在与NSURL建立连接，我需要创建一个绕过所有缓存策略的请求。我见过如下例子：

I am doing a connection to the NSURL and I need to create a request to bypass all the cache policy. I have seen examples such as :

NSURLRequest *request = [NSURLRequest requestWithURL:baseURL cachePolicy:0 timeoutInterval:10];
self.urlConnection = [[[NSURLConnection alloc] initWithRequest:request delegate:self] autorelease];

请问缓存策略0指的是什么？尝试过搜索数字代表什么，但我没有得到任何我需要的答案。谢谢！ ：）

May I ask what does the cache policy 0 refers to? Have tried searching for what the number represents but I'm not getting any answer I need. Thanks! :)

推荐答案

你应该看看 NSURLRequestCachePolicy 枚举，这里0表示NSURLRequestUseProtocolCachePolicy，意味着NSURLRequest不会每次都从服务器加载数据。

you should have a look at NSURLRequestCachePolicy enum, here 0 mean is NSURLRequestUseProtocolCachePolicy, that means NSURLRequest would not load data from server every time.

enum
{
   NSURLRequestUseProtocolCachePolicy = 0,
   NSURLRequestReloadIgnoringLocalCacheData = 1,
   NSURLRequestReloadIgnoringLocalAndRemoteCacheData =4,
   NSURLRequestReloadIgnoringCacheData = NSURLRequestReloadIgnoringLocalCacheData,
   NSURLRequestReturnCacheDataElseLoad = 2,
   NSURLRequestReturnCacheDataDontLoad = 3,
   NSURLRequestReloadRevalidatingCacheData = 5
};
typedef NSUInteger NSURLRequestCachePolicy

这篇关于iOS缓存策略的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！