Setting NavigationBar and TabBar background color with gradient in objective-c

Question

I want to set background color for NavigationBar and TabBar. It must be a gradient containing two hexadecimal colors. How can I made it in objective-c? Thanks,

Answer 1

For the TabBar I had the same problem with my app and I came up with following: in applicationDidFinishLaunching method I created a function to draw a gradient and used an instance of my UITabBarController to set up a correct gradient frame depending on the width of the device.

    - (UIImage *)drawGradientInView:(UITabBarController *) tabBarVC {
   CAGradientLayer *gradient = [CAGradientLayer layer];

  gradient.frame = CGRectMake(CGRectGetMinX(tabBarVC.tabBar.frame), CGRectGetMinY(tabBarVC.tabBar.frame), CGRectGetWidth(tabBarVC.view.frame), CGRectGetHeight(tabBarVC.tabBar.frame));

  gradient.colors = @[(__bridge id)[UIColor colorWithRed:220.0/255.0 green:220.0/255.0 blue:220.0/255.0 alpha:1.0].CGColor, (__bridge id)[UIColor whiteColor].CGColor];
  gradient.startPoint = CGPointMake(0.0, 0.5);
  gradient.endPoint = CGPointMake(0.5, 0.5);

  UIGraphicsBeginImageContext(gradient.bounds.size);
  [gradient renderInContext:UIGraphicsGetCurrentContext()];
  UIImage *gradientImage = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();

  return gradientImage;
} 

get the instance of UITabBarController

UITabBarController *tabVC = (UITabBarController *)[UIApplication sharedApplication].windows.firstObject.rootViewController;

set your gradient

[UITabBar appearance].backgroundImage = [self drawGradientInView:tabVC];

I'm not sure if that's a correct approach but it did work for me.

For NavigationBar, I subclassed it and customised that in layoutSubviews

- (void)layoutSubviews {
    [super layoutSubviews];

    CAGradientLayer *gradient = [CAGradientLayer layer];

    gradient.frame = CGRectMake(0, 0, CGRectGetWidth(self.bounds), CGRectGetHeight(self.bounds) + CGRectGetHeight([UIApplication sharedApplication].statusBarFrame));
    gradient.colors = @[(__bridge id)[UIColor colorWithRed:220.0/255.0 green:220.0/255.0 blue:220.0/255.0 alpha:1.0].CGColor, (__bridge id)[UIColor whiteColor].CGColor];
    gradient.startPoint = CGPointMake(0.0, 0.5);
    gradient.endPoint = CGPointMake(0.5, 0.5);

    UIGraphicsBeginImageContext(gradient.bounds.size);
    [gradient renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *gradientImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    [self setBackgroundImage:gradientImage forBarMetrics:UIBarMetricsDefault];

}

Hope this will help you..

Answer 2

This will help you to change the color of Navigation bar & Tab bar

UINavigationController *navigationController;
...
navigationController.navigationBar.tintColor = [UIColor blackColor];

UITabBarController *tabBarCon;
...
tabBarCon.tabBar.tintColor = [UIColor blueColor];