setNetworkActivityIndi​​catorVisible微调器不显示

Question

正如标题所说,这是一些代码:

- (void)refreshMap {
    NSLog(@"refreshing");
    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
    lat = [[NSNumber numberWithDouble:myUserLocation.coordinate.latitude] stringValue];
    lon = [[NSNumber numberWithDouble:myUserLocation.coordinate.longitude] stringValue];

    NSString *url = [[NSString alloc] initWithFormat:@"http://mywebsite.com/geo_search.json?lat=%@&lon=%@", lat, lon];
    NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:url]
                                              cachePolicy:NSURLRequestUseProtocolCachePolicy
                                          timeoutInterval:60.0];
    [[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
    [url release];
    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
}

网络活动指示器(在状态栏中)根本不显示(不在模拟器中,也不在真实设备上).我该如何解决这个问题？

Answer 1

除非您的代码将控制权返回给runloop,否则不会更新UI.因此,如果您以相同的方法启用和禁用网络指示器,它将永远不会显示.解决方案是打电话

[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];

在你的url连接委托方法(conectionDidFinishLoading:和connection:didFailWithError:).