I try change to background of navigationBar.

Search.h:

```
#import <UIKit/UIKit.h>

@interface Search : UIViewController

@end

```

Search.m:

```
#import "Search.h"

@implementation Search

- (void)viewDidLoad
{

[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.

UIImage *image = [UIImage imageNamed:@"navigation_header.png"];

[self.navigationController.navigationBar setBackgroundImage:image forBarMetrics:UIBarMetricsDefault];

}

```

I can't change navigation background.

Thanks.