尝试显示视图控制器警告

Question

我有以下 ViewController 会在某事完成时显示下一个 ViewController：

Nr1: 我的游戏ViewController 检查游戏是否完成并调用 CheckGameFinished:

-(void) checkGameFinished {
if ([self.gameModel isGameOver]) {

    double delayTimeInSeconds = 3.5;
    dispatch_time_t popTimeDelay = dispatch_time(DISPATCH_TIME_NOW, delayTimeInSeconds * NSEC_PER_SEC);
    dispatch_after(popTimeDelay, dispatch_get_main_queue(), ^(void){

    [progressBarTimer invalidate];

    level2ViewController *govc = [self.storyboard instantiateViewControllerWithIdentifier:@"level2ViewController"];

    [self.finishAudio play];

    [self presentViewController:govc animated:NO completion:^(){
        [self.gameModel clearGameData];

    }];
          });
}
}

然后level2ViewController出现：

- (void)viewDidLoad {
[super viewDidLoad];

double delayTimeInSeconds = 2;
dispatch_time_t popTimeDelay = dispatch_time(DISPATCH_TIME_NOW, delayTimeInSeconds * NSEC_PER_SEC);
dispatch_after(popTimeDelay, dispatch_get_main_queue(), ^(void){


    GameViewController *gvc = [self.storyboard instantiateViewControllerWithIdentifier:@"gameViewController"];

    [self presentViewController:gvc animated:NO completion:nil];


});

}

并调用下一个ViewController，以此类推。

现在我超时收到以下警告：

Warning: Attempt to present GameViewController on level2ViewController whose view is not in the window hierarchy!

Answer 1

不要显示来自 viewDidLoad 的视图控制器，而是从 viewDidAppear: 调用。同样使用 dispatch_after 那样（假设您使用它来希望确保视图在屏幕上而不是出于游戏目的）是一种非常糟糕的做法。
当正在加载的视图控制器完成呈现时（调用 viewDidAppear: 时发生），您可以呈现不同的视图控制器：

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    GameViewController *gvc = [self.storyboard instantiateViewControllerWithIdentifier:@"gameViewController"];
    [self presentViewController:gvc animated:NO completion:nil];
}

Answer 2

当我的 segue 类型是 modal 时，我得到了这个，更改为 push 为我修复了它

尝试显示视图控制器警告

Attempt to present View Controller Warning

objective-c

uiviewcontroller

ios