UINavigationBar's drawRect is not called in iOS 5.0
I've overrided(placed in category, or swizzled) UINavigationBar's drawRect to show custom background. In iOS 5 it's not working. What should I do?
Solution 1:
Setting custom background for UINavigationBar to support iOS5 and iOS4 too!
http://www.mladjanantic.com/setting-custom-background-for-uinavigationbar-what-will-work-on-ios5-and-ios4-too/
http://rogchap.com/2011/06/21/custom-navigation-bar-background-and-custom-buttons/
As you know, until iOS 5 came out, we used drawRect
override in AppDelegate
to customize UINavigationBar
.
But know, iOS 5 give us some new method for styling (and old doesn’t work).
How to build app that will work on iOS 4 and iOS 5 with stylized UINavigationBar
?
You must to do both!
In AppDelegate
use this code:
@implementation UINavigationBar (UINavigationBarCategory)
- (void)drawRect:(CGRect)rect {
UIImage *img = [UIImage imageNamed:@"navbar.png"];
[img drawInRect:rect];
}
@end
and in viewDidLoad
method for iOS5 (in your view implementation):
if ([self.navigationController.navigationBar respondsToSelector:@selector( setBackgroundImage:forBarMetrics:)]){
[self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:@"navbar.png"] forBarMetrics:UIBarMetricsDefault];
}
If you see, here we are asking if navbar will respondToSelector to avoid crash on iOS4!
Solution 2:
Here's a less-ugly solution that works for both iOS4 and 5:
@implementation UINavigationBar (CustomBackground)
- (UIImage *)barBackground
{
return [UIImage imageNamed:@"top-navigation-bar.png"];
}
- (void)didMoveToSuperview
{
//iOS5 only
if ([self respondsToSelector:@selector(setBackgroundImage:forBarMetrics:)])
{
[self setBackgroundImage:[self barBackground] forBarMetrics:UIBarMetricsDefault];
}
}
//this doesn't work on iOS5 but is needed for iOS4 and earlier
- (void)drawRect:(CGRect)rect
{
//draw image
[[self barBackground] drawInRect:rect];
}
@end
Solution 3:
Try to read iOS 5.0 Release Notes
In iOS 5, the UINavigationBar, UIToolbar, and UITabBar implementations have changed so that the drawRect: method is not called unless it is implemented in a subclass. Apps that have re-implemented drawRect: in a category on any of these classes will find that the drawRect: method isn't called. UIKit does link-checking to keep the method from being called in apps linked before iOS 5 but does not support this design on iOS 5 or later.