Warning: Attempt to present on whose view is not in the window hierarchy !, Attempthierarchy

Warning: Attempt to present on whose view is not in the window hierarchy !, Attempthierarchy

When I want to jump from one VC to another

-(Void) presentViewController :( UIViewController *) viewControllerToPresent animated: (BOOL) flag completion :( void (^) (void) completion; you can also use navigation push.

Sometimes this type of Warning occurs: Warning: Attempt to present on whose view is not in the window hierarchy!

Cause: page Jump can only be performed after viewDidLoad and viewDidAppear.

Solution: Make sure that the page Jump is performed after the view load is complete.

First: Wait for the execution of view Load to end with a delay, but this method is time-consuming.

Method 2: Used in viewDidLoad

[Self?mselec=mainthread: @ selector (login) withObject: nilwaitUntilDone: NO];

Write the code for page Jump into the function, and then set waitUntilDone to NO