CODEWITHSUNDEEP
iphoneiosbackgrounduinavigationbarios5
tt.Kilew
tt.Kilew

Reputation: 6084

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?

Upvotes: 19

Views: 14754

Answers (7)

Varun Naharia
Varun Naharia

Reputation: 5428

After iOS 5 - (void)drawRect:(CGRect)rect is not called while we create category for UINavigationBar but you can call -(void)awakeFromNib and add all the code that you want to add.

Upvotes: 0

Manni
Manni

Reputation: 11148

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!

Upvotes: 26

Sergey Lost
Sergey Lost

Reputation: 2551

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.

Upvotes: 11

Robert Varga
Robert Varga

Reputation: 477

Follow this link to make your code compatible with iOS4, 5 and 6.

You just have to make in Photoshop or other software a rectangular with the size of 320x44 or 640x88 (for retina display) and import it to your project

In AppDelegate use this code (in the header between #import and @implementation AppDelegate):

@implementation UINavigationBar (CustomImage)
- (void)drawRect:(CGRect)rect {
    UIImage *image = [UIImage imageNamed:@"top_bar.png"];
    [image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
}
@end

In viewDidLoad use this code for iOS5 and iOS6:

#if defined(__IPHONE_5_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_5_0
    if ([self.navigationController.navigationBar respondsToSelector:@selector( setBackgroundImage:forBarMetrics:)]){
        [self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:@"top_bar.png"] forBarMetrics:UIBarMetricsDefault];
    }
#endif

Upvotes: 0

Nick Lockwood
Nick Lockwood

Reputation: 41005

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

Upvotes: 12

Selvin
Selvin

Reputation: 12493

@implementation UINavigationBar (MyCustomNavBar)

- (void)setBackgroudImage:(UIImage*)image
{
    CGSize imageSize = [image size];
    self.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, self.frame.size.width, imageSize.height);
    UIImageView *backgroundImage = [[UIImageView alloc] initWithImage:image];
    backgroundImage.frame = self.bounds;
    [self addSubview:backgroundImage];
    [backgroundImage release];
}
@end

The above swizzling will allow you to set any custom background image for the UINavigationBar(iOS5 & iOS4).

Upvotes: 1

tt.Kilew
tt.Kilew

Reputation: 6084

There's some possible solutions:

Quickest fix For laziest of us :

@interface MyNavigationBar : UINavigationBar

@end

@implementation MyNavigationBar

- (void)drawRect:(CGRect)rect {

}

@end

@implementation UINavigationBar (BecauseIMLazyHacks)
/*
 Another Ugly hack for iOS 5.0 support
*/
+ (Class)class {
  return NSClassFromString(@"MyNavigationBar");
}

-(void)drawRect:(CGRect)rect {

  CGContextRef context = UIGraphicsGetCurrentContext();
  CGContextTranslateCTM(context, 0, self.frame.size.height);
  CGContextScaleCTM(context, 1.0, -1.0);

  CGContextDrawImage(context, CGRectMake(0, 0, 
  self.frame.size.width, self.frame.size.height), barBackground.CGImage);      

}
@end

Again. It works, but You shouldn't do it like this.

Another way, as suggested in WWDC'11 is to override UINavigationBar (Create MyNavigationBar) and initialize UINavigationController from xib like here :

http://www.iosdevnotes.com/2011/09/custom-uinavigationbars-techniques/

And finally, use logic flow switch for iOS5.0 and iOS5.0- Use new API where it's possible.

Categories is wrong path, Swizzling is wrong path. (They're just whispering in your ears:"Give yourself to the Dark Side. It is the only way you can save your apps.")

Upvotes: 8

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