在iOS8中使用splitViewController:willChangeToDisplayMode:时如何显示BarButtonim

我的应用程序的结构如下所示：

UISplitViewController:

the master:NavigationController1->UITableViewController

the detail:NavigationController2->UIWebViewController

我想在iPad上以人像模式观看时展示巴布顿风格 我知道如何通过willHideViewController在iOS7中实现它：

-(void)splitViewController:(UISplitViewController *)svc willHideViewController:(UIViewController *)aViewController withBarButtonItem:(UIBarButtonItem *)barButtonItem forPopoverController:(UIPopoverController *)pc{
        barButtonItem.title = @"Course";
        self.navigationItem.leftBarButtonItem = barButtonItem;
}

-(void)splitViewController:(UISplitViewController *)svc willShowViewController:(UIViewController *)aViewController invalidatingBarButtonItem:(UIBarButtonItem *)barButtonItem{
    if (barButtonItem == self.navigationItem.leftBarButtonItem) {
         self.navigationItem.leftBarButtonItem = nil;
    }
}

但是，iOS 8中不推荐使用此方法，我尝试使用：

-(void)splitViewController:(UISplitViewController *)svc willChangeToDisplayMode:(UISplitViewControllerDisplayMode)displayMode{
    if (displayMode == UISplitViewControllerDisplayModePrimaryHidden) {
        self.navigationItem.leftBarButtonItem = svc.displayModeButtonItem;
    }else{
        self.navigationItem.leftBarButtonItem = nil;
    }
}

此方法仅在显示模式更改时有效，但在应用程序首次以纵向启动时无效。

---

因此，如何在首次以纵向方向加载应用程序时显示BarButtonim。

当视图控制器显示时，您可以添加条形按钮：

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

    if (self.splitViewController.displayMode == UISplitViewControllerDisplayModePrimaryHidden)
    {
        UIBarButtonItem *barButtonItem = self.splitViewController.displayModeButtonItem;
        barButtonItem.title = @"Show master";
        self.navigationItem.leftBarButtonItem = barButtonItem;
    }
}

---

这只会在主控当前隐藏时添加按钮。

谢谢，它可以工作，但有一个符号“@gao6708我发现最好的解决方案是，如果你在导航栏中添加你自己的uibarbuttonite。请看：这是Swift，但您应该能够轻松地翻译它。请记住在

splitViewController:willChangeToDisplayMode:

中设置相同的按钮，谢谢，获取它<代码>self.navigationItem.leftBarButtonItem=[[UIBarButtonItem alloc]initWithTitle:@“课程”样式：self.splitViewController.displayModeButtonItem.style目标：self.splitViewController.displayModeButtonItem.target操作：self.splitViewController.displayModeButtonItem.action]

-(void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];

    if (self.splitViewController.displayMode == UISplitViewControllerDisplayModePrimaryHidden){
        self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Course" style:self.splitViewController.displayModeButtonItem.style target:self.splitViewController.displayModeButtonItem.target action:self.splitViewController.displayModeButtonItem.action];
    }
}

-(void)splitViewController:(UISplitViewController *)svc willChangeToDisplayMode:(UISplitViewControllerDisplayMode)displayMode{
    if (displayMode == UISplitViewControllerDisplayModePrimaryHidden) {
        self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Course" style:svc.displayModeButtonItem.style target:svc.displayModeButtonItem.target action:svc.displayModeButtonItem.action];
    }else{
        self.navigationItem.leftBarButtonItem = nil;
    }
}