iphone - 不要调用连接 :(NSURLConnection *)connection didReceiveData:(NSData *)data

Question

我想从某个服务器下载一些文件。下载文件的功能在 Thread 中运行。所以，你可以在这里看到它:

    NSURL *url = [NSURL URLWithString:fileDataBaseURL];
NSURLRequest *theRequest=[NSURLRequest requestWithURL:url
                                          cachePolicy:NSURLRequestUseProtocolCachePolicy
                                      timeoutInterval:60.0];

NSURLConnection *theConnection = [NSURLConnection connectionWithRequest:theRequest delegate:self];
if (theConnection) {
    [[NSFileManager defaultManager] createFileAtPath:fileDataBaseEnc contents:nil attributes:nil];
    self._handleDataBaseEnc = [NSFileHandle fileHandleForUpdatingAtPath:fileDataBaseEnc];
} else {
    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];

}

我也有功能:

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    [_handleDataBaseEnc seekToEndOfFile];

    NSMutableData *receivedData = [NSMutableData data];
    [receivedData setLength:0];
    [receivedData appendData:data];

    [_handleDataBaseEnc writeData:receivedData];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    [_handleDataBaseEnc closeFile];
    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
}

 - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
 {
     [_handleDataBaseEnc closeFile];
     [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
 }

问题

为什么这三个功能不起作用？它不会调用，永远不会。

我该如何解决？

Answer 1

来自 Art 的回答:NSURLConnection delegate methods are not called

尝试在主线程上运行操作:

NSURLConnection * connection = [[NSURLConnection alloc] 
                                initWithRequest:request
                                       delegate:self startImmediately:NO];

[connection scheduleInRunLoop:[NSRunLoop mainRunLoop] 
                      forMode:NSDefaultRunLoopMode];
[connection start];