Tab隐藏导航栏跳转到Nav控制器的导航颜色黑边问题

假如从A跳转到B

A是tab的一个界面，导航隐藏，在A中：

- (void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
    self.tabBarController.tabBar.translucent = YES;
    [self.navigationController setNavigationBarHidden:YES animated:animated];
    self.fd_prefersNavigationBarHidden = YES;
  
}
- (void)viewWillDisappear:(BOOL)animated{
    [super viewWillDisappear:animated];
    self.tabBarController.tabBar.translucent = NO;
    [self.navigationController setNavigationBarHidden:NO animated:animated];
}

B是导航栏，在B中：

-(void)viewWillAppear:(BOOL)animated

{

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

    //设置导航条颜色

    self.navigationController.navigationBar.barStyle =UIStatusBarStyleLightContent;

    self.navigationController.navigationBar.barTintColor = [UIColor colorWithRed:0.46 green:0.77 blue:0.86 alpha:1.0];

    //设置返回按钮颜色

    self.navigationController.navigationBar.tintColor = [UIColor whiteColor];

  //设置导航栏标题颜色

    NSDictionary *dict = @{NSForegroundColorAttributeName : [UIColor whiteColor]};

    [ self.navigationController.navigationBar setTitleTextAttributes:dict];

    [super viewWillAppear:YES];

//自定义白色的返回按钮图片

    UIButton *leftbutton=[[UIButton alloc]initWithFrame:CGRectMake(0, 0, 20, 20)];

    [leftbutton setImage:[UIImage imageNamed:@"goBack"] forState:UIControlStateNormal];

    UIBarButtonItem *rightitem=[[UIBarButtonItem alloc]initWithCustomView:leftbutton];

    [leftbutton addTarget:self action:@selector(backToViewController) forControlEvents:UIControlEventTouchUpInside];

    UIBarButtonItem *negativeSpacer = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];

    negativeSpacer.width = -18;

    self.navigationItem.leftBarButtonItems = [NSArray arrayWithObjects:negativeSpacer,rightitem, nil];

}

-(void)viewWillDisappear:(BOOL)animated{

    [super viewWillDisappear:animated];

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

}

完美解决所有问题