iPhone 导航栏中的标题和副标题

Question

在我的应用程序中，我希望导航栏显示标题和副标题。

为此，我将以下代码添加到我的 View Controller 中:

// Replace titleView
CGRect headerTitleSubtitleFrame = CGRectMake(0, 0, 200, 44);    
UIView* _headerTitleSubtitleView = [[[UILabel alloc] initWithFrame:headerTitleSubtitleFrame] autorelease];
_headerTitleSubtitleView.backgroundColor = [UIColor clearColor];
_headerTitleSubtitleView.autoresizesSubviews = YES;

CGRect titleFrame = CGRectMake(0, 2, 200, 24);  
UILabel *titleView = [[[UILabel alloc] initWithFrame:titleFrame] autorelease];
titleView.backgroundColor = [UIColor clearColor];
titleView.font = [UIFont boldSystemFontOfSize:20];
titleView.textAlignment = UITextAlignmentCenter;
titleView.textColor = [UIColor whiteColor];
titleView.shadowColor = [UIColor darkGrayColor];
titleView.shadowOffset = CGSizeMake(0, -1);
titleView.text = @"";
titleView.adjustsFontSizeToFitWidth = YES;
[_headerTitleSubtitleView addSubview:titleView];

CGRect subtitleFrame = CGRectMake(0, 24, 200, 44-24);   
UILabel *subtitleView = [[[UILabel alloc] initWithFrame:subtitleFrame] autorelease];
subtitleView.backgroundColor = [UIColor clearColor];
subtitleView.font = [UIFont boldSystemFontOfSize:13];
subtitleView.textAlignment = UITextAlignmentCenter;
subtitleView.textColor = [UIColor whiteColor];
subtitleView.shadowColor = [UIColor darkGrayColor];
subtitleView.shadowOffset = CGSizeMake(0, -1);
subtitleView.text = @"";
subtitleView.adjustsFontSizeToFitWidth = YES;
[_headerTitleSubtitleView addSubview:subtitleView];

_headerTitleSubtitleView.autoresizingMask = (UIViewAutoresizingFlexibleLeftMargin |
                                      UIViewAutoresizingFlexibleRightMargin |
                                      UIViewAutoresizingFlexibleTopMargin |
                                      UIViewAutoresizingFlexibleBottomMargin);

self.navigationItem.titleView = _headerTitleSubtitleView;

并且还实现了一个方法:

-(void) setHeaderTitle:(NSString*)headerTitle andSubtitle:(NSString*)headerSubtitle {
    assert(self.navigationItem.titleView != nil);
    UIView* headerTitleSubtitleView = self.navigationItem.titleView;
    UILabel* titleView = [headerTitleSubtitleView.subviews objectAtIndex:0];
    UILabel* subtitleView = [headerTitleSubtitleView.subviews objectAtIndex:1];
    assert((titleView != nil) && (subtitleView != nil) && ([titleView isKindOfClass:[UILabel class]]) && ([subtitleView isKindOfClass:[UILabel class]]));
    titleView.text = headerTitle;
    subtitleView.text = headerSubtitle;
}

一切都很顺利，谢谢。

只不过当 iPhone 旋转到横向时，标题+副标题不会像导航项的默认标题那样自动缩小。

有什么指点吗？

谢谢!

Answer 1

将 titleView 和 subtitleView 标签放入 View Controller 的属性中，以便您可以从任何方法访问它们。然后，在旋转 View Controller 时，调整标签的大小:

- (void) willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
    [self adjustLabelsForOrientation:toInterfaceOrientation];
}

- (void) adjustLabelsForOrientation:(UIInterfaceOrientation)orientation {
    if (orientation == UIInterfaceOrientationLandscapeLeft || orientation == UIInterfaceOrientationLandscapeRight) {
        titleView.font = [UIFont boldSystemFontOfSize:16];
        subtitleView.font = [UIFont boldSystemFontOfSize:11];
    }
    else if (orientation == UIInterfaceOrientationPortrait || orientation == UIInterfaceOrientationPortraitUpsideDown) {
        titleView.font = [UIFont boldSystemFontOfSize:20];
        subtitleView.font = [UIFont boldSystemFontOfSize:13];
    }
}