UINavigationBar 自定义背景图片

Question

I used these suggested solutions to give my UINavigationBar a custom image. (To make it more explicit: I added a category to UINavigationBar in my AppDelegate.m file). This worked fine so far and I didn't have any problems. Now however, I was running my app on the recent iOS5 beta. The UINavigationBar is blank now again.

Since all the other apps I have installed, that use a custom image, still behave the same there must be something "wrong" in my code I guess, that iOS5 now doesn't support anymore.

So does anybody have an idea what could be the problem with my adoption of the above mentioned solutions?

The only way I found to make it work was to create a real subclass of UINavigationBar and then in all the views tell IB to use that custom class. Not as elegant, though...

Answer 1

To support both versions, you need to ask if there is setBackgroundImage:forBarMetrics: method.

Take a look at my blogpost about it: http://www.mladjanantic.com/setting-custom-background-for-uinavigationbar-what-will-work-on-ios5-and-ios4-too/

Answer 2

Use this code

        UIImage *backgroundImage = [UIImage imageNamed:@"strip.png"];
        [upnavbar setBackgroundImage:backgroundImage forBarMetrics:UIBarMetricsDefault];

this wil work.

Answer 3

One more possible "hacky" solution is to create a custom view and insert it to UINavigationBar as a subView - may be it will still work:

UIView *backgroundView = ...
[navigationBar insertSubview:backgroundView atIndex:0];

Or check updated UINavigationBar class reference in iOS5 docs for built-in method to set custom background

Answer 4

This worked for me on my toolBar

//toolBar background image set based on iOS version
    [[UIDevice currentDevice] systemVersion];

    if ([[[UIDevice currentDevice] systemVersion] floatValue] > 4.9) {

        //iOS 5
        UIImage *toolBarIMG = [UIImage imageNamed: @"toolBar_brown.png"];  

        if ([toolBar respondsToSelector:@selector(setBackgroundImage:forToolbarPosition:barMetrics:)]) { 
            [toolBar setBackgroundImage:toolBarIMG forToolbarPosition:0 barMetrics:0]; 
        }

    } else {

        //iOS 4
        [toolBar insertSubview:[[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"toolBar_brown.png"]] autorelease] atIndex:0]; 

    }