是否可以防止NSURLRequest在请求后缓存数据或删除缓存的数据？ [英] Is it possible to prevent an NSURLRequest from caching data or remove cached data following a request?

问题描述

在iPhone上，我使用NSURLRequest对一大块数据执行HTTP请求。对象分配峰值和我相应地分配数据。当我完成数据，我释放它相应 - 但仪器不显示任何数据被释放！

我的理论是，默认HTTP请求缓存，但是 - 我不想我的iPhone应用程序缓存这些数据。

有没有办法在请求后清除此缓存，或阻止任何数据首先被缓存？

  NSMutableURLRequest * theRequest = [NSMutableURLRequest requestWithURL： [NSURL URLWithString：url]]; 
 theRequest.cachePolicy = NSURLRequestReloadIgnoringLocalCacheData; 
  

但没有任何内容释放内存！

任何帮助将非常感谢。

谢谢！
Nick。

解决方案

通常这样更容易创建请求

  NSURLRequest * request = [NSURLRequest requestWithURL：url 
 cachePolicy：NSURLRequestReloadIgnoringCacheData 
 timeoutInterval：60.0]; 
  

然后创建连接

  NSURLConnection * conn = [NSURLConnection connectionWithRequest：request 
 delegate：self]; 
  

并在代理上实现连接：willCacheResponse：

   - （NSCachedURLResponse *）connection：（NSURLConnection *）connection willCacheResponse：（NSCachedURLResponse *）cachedResponse {
 return nil; 
} 
  

On iPhone, I perform a HTTP request using NSURLRequest for a chunk of data. Object allocation spikes and I assign the data accordingly. When I finish with the data, I free it up accordingly - however instruments doesn't show any data to have been freed!

My theory is that by default HTTP requests are cached, however - I don't want my iPhone app to cache this data.

Is there a way to clear this cache after a request or prevent any data from being cached in the first place?

I've tried using all the cache policies documented a little like below:

NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:url]];
theRequest.cachePolicy = NSURLRequestReloadIgnoringLocalCacheData;

but nothing seems to free up the memory!

Any help here would be much appreciated.

Thanks! Nick.

解决方案

Usually it's easier to create the request like this

NSURLRequest *request = [NSURLRequest requestWithURL:url
      cachePolicy:NSURLRequestReloadIgnoringCacheData
      timeoutInterval:60.0];

Then create the connection

NSURLConnection *conn = [NSURLConnection connectionWithRequest:request
       delegate:self];

and implement the connection:willCacheResponse: method on the delegate. Just returning nil should do it.

- (NSCachedURLResponse *)connection:(NSURLConnection *)connection willCacheResponse:(NSCachedURLResponse *)cachedResponse {
  return nil;
}

这篇关于是否可以防止NSURLRequest在请求后缓存数据或删除缓存的数据？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！