UIBarButtonItem UIBarMetricsDefault example in Objective C (iOS).

UIBarButtonItem UIBarMetricsDefault

UIBarMetrics
Constants to specify metrics to use for appearance.

typedef enum {
UIBarMetricsDefault,
UIBarMetricsLandscapePhone,
} UIBarMetrics;
Constants
UIBarMetricsDefault
Specifies default metrics for the device.
UIBarMetricsLandscapePhone
Specifies metrics for landscape orientation using the phone idiom.

UIBarButtonItem UIBarMetricsDefault example.

[[UIBarButtonItem appearanceWhenContainedIn:[UINavigationBar class], nil] setBackgroundVerticalPositionAdjustment:-3 forBarMetrics:UIBarMetricsDefault];
    [[UIBarButtonItem appearanceWhenContainedIn:[UINavigationBar class], nil] setBackButtonBackgroundVerticalPositionAdjustment:-3 forBarMetrics:UIBarMetricsDefault];

    [[UIBarButtonItem appearanceWhenContainedIn:[UIToolbar class], nil] setBackgroundVerticalPositionAdjustment:3 forBarMetrics:UIBarMetricsDefault];
    [[UIBarButtonItem appearanceWhenContainedIn:[UIToolbar class], nil] setBackButtonBackgroundVerticalPositionAdjustment:3 forBarMetrics:UIBarMetricsDefault];

Example of [UIBarButtonItem UIBarMetricsDefault].

-(void)toggleAppearanceStyles:(NSNotification *)note {

    UIImage *barButtonBgImage = nil;
    UIImage *barButtonBgImageActive = nil;

 if([note.userInfo[@"flag"] boolValue]) {

        barButtonBgImage = [[UIImage imageNamed:@"g_barbutton.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(15, 4, 15, 4)];
        barButtonBgImageActive = [[UIImage imageNamed:@"g_barbutton_active.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(15, 4, 15, 4)];
    }

    [[UIBarButtonItem appearance] setBackgroundImage:barButtonBgImage forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];
    [[UIBarButtonItem appearance] setBackgroundImage:barButtonBgImageActive forState:UIControlStateSelected barMetrics:UIBarMetricsDefault];

}

UIBarButtonItem UIBarMetricsDefault example.

UIImage *doneBackgroundImage = [[UIImage imageNamed:@"button_done.png"]
   resizableImageWithCapInsets:UIEdgeInsetsMake(0, 4, 0, 4)];

[[UIBarButtonItem appearance] setBackgroundImage:doneBackgroundImage
                                            forState:UIControlStateNormal
                                               style:UIBarButtonItemStyleDone
                                          barMetrics:UIBarMetricsDefault];

End of UIBarButtonItem UIBarMetricsDefault example article.