iphone - NSURLConnection 不刷新

Question

我有一个 NSURLConnection，每次调用 -(void)viewWillAppear:animated 时都会调用它(仅用于测试)

我就是这样做的

receivedData = [[NSMutableData data] retain];
NSString *urlString = @"<URL hidden>";
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:urlString] cachePolicy:NSURLRequestReturnCacheDataElseLoad timeoutInterval:30.0];
[NSURLConnection connectionWithRequest:request delegate:self];

然后我有这三个委托(delegate)方法:

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [receivedData appendData:data];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    NSString *returnString = [[NSString alloc] initWithData:receivedData encoding:NSUTF8StringEncoding];
    usersPhotos = [[NSMutableArray alloc] initWithArray:[[returnString JSONValue] objectForKey:@"data"]];
    [self loadAnnotations];

    NSLog(@"%@", returnString);

    [returnString release];
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    [self loadAnnotations];
}

尽管我确信 returnString 应该更改(我可以访问 urlString 中的网站并确认它已更改)，但它始终是相同的。

就好像它重用了从第一个连接检索的数据。

有谁知道这是为什么吗？

Answer 1

这应该是您的缓存策略，我将在一秒钟内更新正确的信息。

<小时/>

更新

尝试将您的 cahce 策略设置为:cachePolicy:NSURLRequestReloadIgnoringCacheData

应该是:

NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:urlString] cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:30.0];