Load order of Controller view Initwithnibname >>> viewdidload >>> viewwillappear >>> viewdidappear

-(void) Viewwillappear: (BOOL) animated

{

self. Navigationcontroller. Navigationbarhidden=NO; Deng Chao: Put in willappear, cannot be placed in Viewdidload (because Viewdidload is executed first, then Viewwillappear is executed. And when the controller does not have the dealloc,viewdidload will not be executed)

}

Execution order:

Initwithnibname >>> viewdidload >>> viewwillappear >>> viewdidappear

The value of the property passed to the class is empty in the Initwithnibname method and needs to be used in viewdidload.

Load order of Controller view Initwithnibname >>> viewdidload >>> viewwillappear >>> viewdidappear