iOS缓存策略

Question

我正在连接NSURL,我需要创建一个绕过所有缓存策略的请求.我见过例如:

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但我没有得到任何我需要的答案.谢谢!:)

Answer 1

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

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