为什么我的TabBar按钮不会在iPad上自动显示？

Question

我正在构建一个通用的iOS应用程序,iPad版本使用SplitViewController.在popover视图中,我有一个带有两个按钮的UITabBarController.当它在iPhone上运行时,TabBar按钮正确拉伸以填充视图的整个宽度......

...但是在iPad上,在弹出视图中,按钮不会伸展以填满整个宽度......

我正在以编程方式创建UITabBarController ...

InspectionTabBarViewController *inspectionTabBarVC;
    InspectionListViewController *inspectionListVC;
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

 if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {

        inspectionListVC = [[InspectionListViewController alloc] initWithSunday:NO];
        inspectionListVC.managedObjectContext = self.managedObjectContext;
        UINavigationController *calendarNavVC = [[UINavigationController alloc] initWithRootViewController:inspectionListVC];
        calendarNavVC.title = @"Calendar";

        InspectionMapViewController *mapViewVC = [[InspectionMapViewController alloc] initWithNibName:@"InspectionMapView_iPhone" bundle:nil];
        UINavigationController *mapdNavVC = [[UINavigationController alloc] initWithRootViewController:mapViewVC];
        mapdNavVC.title = @"Map";

        inspectionTabBarVC = [[InspectionTabBarViewController alloc] init];
        [inspectionTabBarVC addChildViewController:calendarNavVC];
        [inspectionTabBarVC addChildViewController:mapdNavVC];
        self.window.rootViewController = inspectionTabBarVC;
    } 
    else 
    {
        inspectionListVC = [[InspectionListViewController alloc] initWithSunday:NO];
        UINavigationController *calendarNavVC = [[UINavigationController alloc] initWithRootViewController:inspectionListVC];
        calendarNavVC.title = @"Calendar";

        InspectionMapViewController *mapViewVC = [[InspectionMapViewController alloc] initWithNibName:@"InspectionMapView_iPad" bundle:nil];
        UINavigationController *mapdNavVC = [[UINavigationController alloc] initWithRootViewController:mapViewVC];
        mapdNavVC.title = @"Map";

        inspectionTabBarVC = [[InspectionTabBarViewController alloc] init];
        [inspectionTabBarVC addChildViewController:calendarNavVC];
        [inspectionTabBarVC addChildViewController:mapdNavVC];

        DetailViewController *detailViewController = [[DetailViewController alloc] initWithNibName:@"DetailViewController_iPad" bundle:nil];
        UINavigationController *detailNavigationController = [[UINavigationController alloc] initWithRootViewController:detailViewController];

        self.splitViewController = [[UISplitViewController alloc] init];
        self.splitViewController.delegate = detailViewController;
        self.splitViewController.viewControllers = [NSArray arrayWithObjects:inspectionTabBarVC, detailNavigationController, nil];

        self.window.rootViewController = self.splitViewController;
        inspectionListVC.detailViewController = detailViewController;
        inspectionListVC.managedObjectContext = self.managedObjectContext;

        detailViewController.detailViewControllerDelegate = inspectionListVC;
    }

    [self.window makeKeyAndVisible];

我还尝试使用以下语句在InspectionTabBarViewController的loadView方法中设置autoResizeMask ...

self.tabBar.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleBottomMargin | UIViewAutoresizingFlexibleWidth;

......但那也没有用.如何让UITabBar按钮填充整个视图宽度？

非常感谢您的帮助!

Answer 1

将UITabBar财产更改itemPositioning为UITabBarItemPositioningFill:

self.tabBar.itemPositioning = UITabBarItemPositioningFill;

Swift版本:

tabBar.itemPositioning = .fill

UITabBar itemPositioning参考