NSURLConnection不刷新

Question

我有一个NSURLConnection,我每次-(void)viewWillAppear:animated都调用它(这只是现在,它仅用于测试)

我是这样做的

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];
}

即使我确定returnString应该改变(我可以访问该网站urlString并确认它已经改变)它总是一样的.

就好像它重用了从第一个连接中检索的数据.

有人知道为什么吗？

Answer 1

它应该是您的缓存策略,我将在一秒钟内使用正确的信息进行更新.

UPDATE

尝试将您的cahce政策设置为: cachePolicy:NSURLRequestReloadIgnoringCacheData

它应该是:

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