NSRangeException indexOutOfBound

Question

我使用的是我在另一个应用程序中编写的代码。在另一个应用程序中，代码运行良好。我所做的是，当加载splashViewController时，slideShow的图像正在被下载和缓存。下载完成后，它将显示mainviewcontroller，这是一个可维护的视图控制器。下面是我使用的代码：

 UIImage* tabBarBackground = [UIImage imageNamed:@"tabBar.png"];
 [[UITabBar appearance] setBackgroundImage:tabBarBackground];
 UITabBarController *rootViewController = [storyboard instantiateViewControllerWithIdentifier:@"barController"];
 UITabBar *tabBar = rootViewController.tabBar;
 UITabBarItem *tabBarItem1 = tabBar.items[0];// the error here happening event if i comment out this line the error is hapen at the next uibar items 
 UIImage *selectedLogo = [[UIImage imageNamed:@"productSelected"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
 UIImage *unselectedLogo = [[UIImage imageNamed:@"product"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
 [tabBarItem1 setImage:unselectedLogo];
 [tabBarItem1 setSelectedImage:selectedLogo];
 [tabBarItem1 setTitle:@"My Product"];
 UITabBarItem *tabBarItem2 = tabBar.items[1];
 UIImage *selectednews = [[UIImage imageNamed:@"notificationSelected"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
 UIImage *unselectednews = [[UIImage imageNamed:@"notification"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
 [tabBarItem2 setImage:unselectednews];
 [tabBarItem2 setSelectedImage:selectednews];
 [tabBarItem2 setTitle:@"Notifications"];
 UITabBarItem *tabBarItem3 = [tabBar.items objectAtIndex:2];
 UIImage *selectedLocation = [[UIImage imageNamed:@"locationSelected"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
 UIImage *unselectedLocation = [[UIImage imageNamed:@"location"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
 [tabBarItem3 setImage:unselectedLocation];
 [tabBarItem3 setSelectedImage:selectedLocation];
 [tabBarItem3 setTitle:@"Locate Us"];
 UITabBarItem *tabBarItem4 = tabBar.items[3];
 UIImage *selectedaboutus = [[UIImage imageNamed:@"moreSelected"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
 UIImage *unselectedaboutus = [[UIImage imageNamed:@"more"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
 [tabBarItem4 setImage:unselectedaboutus];
 [tabBarItem4 setSelectedImage:selectedaboutus];
 [tabBarItem4 setTitle:@"More"];
 [self.loadingActivityIndicator stopAnimating];
 [self.navigationController popToRootViewControllerAnimated:YES];
 [self presentViewController:rootViewController animated:YES completion:nil];

Answer 1

请先对tabbar.items进行计数检查，然后访问所有选项卡栏项目：

if(tabbar.items.count==tabCount)   //tabCount is number of tabs in your tabbar
{
    UITabBarItem *tabBarItem1 = tabBar.items[0];
    //<remaining code>
}else
{
   //either tabbar is nil or tabbar doesn't not have any tabs, so handle accordingly
}

此外，由于the栏在另一个应用程序中工作正常，请检查您的StoryBoard是否正确地创建并绑定了rootViewController的the栏。

这里有一个很好的帖子，详细介绍了使用故事板正确创建选项卡栏的步骤，这些步骤可以帮助您调试/验证是否正确地创建了绑定和segues：https://guides.codepath.com/ios/Using-Tab-Bar-Controllers