导航栏隐藏黑边问题

-(void)viewWillAppear:(BOOL)animated

{

[super viewWillAppear:YES];

[self.navigationController setNavigationBarHidden:YES animated:YES];

}

-(void)viewWillDisappear:(BOOL)animated

{

[super viewWillDisappear:YES];

[self.navigationController setNavigationBarHidden:NO animated:YES];

}