导航栏中不出现小延迟后添加的 iOS 搜索栏

Question

如果我在延迟 0.1 秒后添加搜索栏，则它不会出现在导航栏中。如果我将延迟更改为 0.5 秒，它就会出现。这是因为当延迟很短时它会在推送动画期间运行吗？如何让它在 0.1 秒延迟后显示？

- (void)viewDidLoad
{
    [super viewDidLoad];
    double delayInSeconds = .1;
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
    dispatch_after(popTime, dispatch_get_main_queue(), ^{
        self.definesPresentationContext = YES;
        UISearchController *searchController = [[UISearchController alloc] initWithSearchResultsController:nil];
        [self.navigationItem setSearchController:searchController];
        [self.navigationItem setHidesSearchBarWhenScrolling:NO];
    });
}

Answer 1

将您的代码放入此 block 中...它会延迟 1 秒，如果有任何问题请告诉我

DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 0.1, execute: {


        })