- (void)viewDidLoad {
[super viewDidLoad];
[self updateNavigationBarBGColor];
self.title = @"导航title";
}
//设置导航条的背景为渐变色
-
(void)updateNavigationBarBGColor
{
CALayer * bgLayer = [self gradientBGLayerForBounds:CGRectMake(0, 0, self.navigationController.navigationBar.frame.size.width, self.navigationController.navigationBar.frame.size.height)];
UIGraphicsBeginImageContext(bgLayer.bounds.size);
[bgLayer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * bgAsImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();if (bgAsImage != nil)
{
[self.navigationController.navigationBar setBackgroundImage:bgAsImage forBarMetrics:UIBarMetricsDefault];
}
else
{
NSLog(@"Failded to create gradient bg image, user will see standard tint color gradient.");
}
} (CALayer *)gradientBGLayerForBounds:(CGRect)bounds
{
CAGradientLayer *gradientLayer = [CAGradientLayer layer];
gradientLayer.colors = @[(__bridge id)[UIColor redColor].CGColor, (__bridge id)[UIColor yellowColor].CGColor];
gradientLayer.locations = @[@0, @1.0];
gradientLayer.startPoint = CGPointMake(0, 0);
gradientLayer.endPoint = CGPointMake(1.0, 0);
gradientLayer.frame = bounds;
return gradientLayer;
}
