当屏幕切换到横向模式时,我想为导航栏设置更大的背景。所以这就是我在视图控制器中所做的:
- (void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration
{
    UIDeviceOrientation deviceOrientation = toInterfaceOrientation;
    if([[UINavigationBar class] respondsToSelector:@selector(appearance)]) {
        [self.navigationController.navigationBar setBackgroundImage: [UIImageHelper createTopBar: deviceOrientation] forBarMetrics: UIBarMetricsDefault];
    }
    else
        [self.navigationController.navigationBar setBackgroundColor: [UIColor colorWithPatternImage: [UIImageHelper createTopBar: [[UIDevice currentDevice] orientation]]]];
}
这是createTopBar方法:
+ (UIImage *)createTopBar: (UIDeviceOrientation) orientation {
    // Create a new image context
    CGSize size;
    if (orientation == UIInterfaceOrientationLandscapeLeft || orientation == UIInterfaceOrientationLandscapeRight){
        if ([UIDevice isiPhone5]) {
            size = CGSizeMake(568, 34);
            UIGraphicsBeginImageContextWithOptions(CGSizeMake(568, 34), NO, 0.0);
        }
        else if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
            size = CGSizeMake(1024, 44);
            UIGraphicsBeginImageContextWithOptions(size, NO, 0.0);
        }
        else {
            size = CGSizeMake(480, 34);
            UIGraphicsBeginImageContextWithOptions(CGSizeMake(480, 34), NO, 0.0);
        }
    }
    else{
        if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
            size = CGSizeMake(768, 44);
            UIGraphicsBeginImageContextWithOptions(CGSizeMake(768, 44), NO, 0.0);
        }
        else if ([UIDevice isiPhone5]) {
            size = CGSizeMake(320, 44);
            UIGraphicsBeginImageContextWithOptions(CGSizeMake(320, 44), NO, 0.0);
        }
        else {
            size = CGSizeMake(320, 44);
            UIGraphicsBeginImageContextWithOptions(CGSizeMake(320, 44), NO, 0.0);
        }
    }
    UIImage * image = [UIImage imageNamed: @"top_bar_without_title"];
    [image drawInRect:CGRectMake(0, 0, size.width, size.height+4)];
    UIImage * destImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return destImage;
}
结果在纵向模式下很好:

这在 iOS 6 的横向模式下也很有效:

但这就是 iOS 7 横向模式的结果:

您可以看到状态栏与导航栏重叠,并且导航栏底部有一些额外的空间。(附带说明,我编辑了 info.plist 文件以修复重叠状态栏问题。这仅在我尝试为导航栏设置新背景图像时发生。)您对这个问题有什么建议吗?如果你这样做,请告诉我,谢谢。