ActivityView没有显示

Question

我正在尝试向我的应用添加下载进度视图，虽然它在调试预览中显示，但它实际上并未显示在设备上。任何人都可以向我解释这个吗？

以下是调试和一些代码的屏幕截图：

- (void)updateDownloadProgressWithBatchIndex:(int)index contentName:(NSString *)name
{
    CGSize size = self.view.bounds.size;

    _loadingView = [[UIView alloc] initWithFrame:CGRectMake(75, 155, 170, 170)];
    _loadingView.backgroundColor = [UIColor blackColor];
    _loadingView.clipsToBounds = YES;
    _loadingView.layer.cornerRadius = 10.0;
    [_loadingView setCenter:CGPointMake(size.width/2, size.height/2)];

    _activityView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];
    _activityView.frame = CGRectMake(65, 40, _activityView.bounds.size.width,     _activityView.bounds.size.height);
    _activityView.hidden = NO;
    [_activityView setCenter:CGPointMake(size.width/2, size.height/2)];
    [_loadingView addSubview:_activityView];

    _loadingLabel = [[UILabel alloc] initWithFrame:CGRectMake(20, 115, 130, 22)];
    _loadingLabel.backgroundColor = [UIColor clearColor];
    _loadingLabel.textColor = [UIColor whiteColor];
    _loadingLabel.adjustsFontSizeToFitWidth = YES;
    _loadingLabel.textAlignment = UITextAlignmentCenter;
    _loadingLabel.text = [NSString stringWithFormat:@"Batch %i downloading...", index];
    [_loadingView addSubview:_loadingLabel];

    [self.view addSubview:_loadingView];
    _loadingView.hidden = NO;
    UIView *v = self.view;
    [_activityView startAnimating];
}

Answer 1

我会猜测 - 它必须是狂野的，因为你拒绝展示你的代码 - 你打电话给updateDownloadProgress后你正在进行同步网络。这就是问题的原因。因此，活动视图无法开始旋转将是诊断性的，真正的问题是同步网络，这是禁忌。