ios - presentViewController 显示白屏 10-15 秒

Question

ChangePasswordPage *vc = [self.storyboard instantiateViewControllerWithIdentifier:@"changedPass5"];
[self presentViewController:vc animated:YES completion:nil];

如果我将这段代码放在 viewDidLoad 中，它会起作用，但是当我在一个函数中运行它时，它仍然起作用，但是在 10-15 秒后出现白屏，然后屏幕正确加载.

这是为什么？

相关代码如下:

dispatch_queue_t queue = dispatch_queue_create("x.x", NULL);
dispatch_async(queue, ^{

    while(true)
    {
        sleep(1);
        checkCacheForRefreshDone = [[NSUserDefaults standardUserDefaults] stringForKey:@"homeScreenRefreshDone"];
        userChangedPassword = [[NSUserDefaults standardUserDefaults] stringForKey:@"userChangedPassword"];


       if ([checkCacheForRefreshDone isEqualToString:@"1"])
        {
            [self installAfterRefresh];    
            [feedHomeTable reloadData];
            [[NSUserDefaults standardUserDefaults] setObject:@"0" forKey:@"homeScreenRefreshDone"];
            [[NSUserDefaults standardUserDefaults] synchronize];
            checkCacheForRefreshDone = @"0";
            [refresh endRefreshing];
            break;
        }

    }

});


-(void)installAfterRefresh
{

    userChangedPassword = [[NSUserDefaults standardUserDefaults] stringForKey:@"userChangedPassword"];

    if ([userChangedPassword isEqualToString:@"1"])
    {
        [self detectPhone];
    }
}

detectPhone使用presentViewController的函数

修复:添加此方法:

[self performSelectorOnMainThread:@selector(detectPhone) withObject:nil waitUntilDone:YES];

Answer 1

尝试在没有 self.storyboard 的情况下编写代码。

改变:

ChangePasswordPage *vc = [self.storyboard instantiateViewControllerWithIdentifier:@"changedPass5"];
[self presentViewController:vc animated:YES completion:nil];

成为:

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
ChangePasswordPage *vc = [storyboard instantiateViewControllerWithIdentifier:@"changedPass5"];
[self presentViewController:vc animated:YES completion:nil];