為什么檢測首次啟動或不啟動方法不起作用

Question

這是我的代碼：

- (void)viewDidLoad
{
    [super viewDidLoad];
    if ([[NSUserDefaults standardUserDefaults] boolForKey:@"HasLaunchedOnce"])
    {
    }
    else
    {
        guideTourViewController *guide=[self.storyboard instantiateViewControllerWithIdentifier:@"GuideTour"];
        guide.modalTransitionStyle=UIModalTransitionStyleCrossDissolve;
        [self presentViewController:guide animated:NO completion:nil];
        [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"HasLaunchedOnce"];
        [[NSUserDefaults standardUserDefaults] synchronize];
        // This is the first launch ever

    }

 } 

為什么即使第一次啟動該應用程序，guideTourViewController仍然不顯示？

Answer 1

似乎有兩個連續的過渡問題，如果我是對的，你可以放在else部分

double delayInSeconds = 2.0;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
    //
    guideTourViewController *guide=[self.storyboard instantiateViewControllerWithIdentifier:@"GuideTour"];
    guide.modalTransitionStyle=UIModalTransitionStyleCrossDissolve;
    [self presentViewController:guide animated:NO completion:nil];
    [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"HasLaunchedOnce"];
    [[NSUserDefaults standardUserDefaults] synchronize];
});

您可以根據需要減少延遲。

希望這會工作..