tabBarItem直到标签栏被窃听

Question

我有一个TabBarController，在我这样的代码定义了两个标签：

NSMutableArray *viewControllerArray = [[NSMutableArray alloc]initWithCapacity:2]; 

DisplayMarketViewController *displayMarketViewController = [[DisplayMarketViewController alloc]init];  
[viewControllerArray addObject:displayMarketViewController]; 
[displayMarketViewController release]; 

DisplayDifferenceMarketViewController *displayDifferenceMarketViewController = [[DisplayDifferenceMarketViewController alloc]init]; 
[viewControllerArray addObject:displayDifferenceMarketViewController]; 
[displayDifferenceMarketViewController release]; 
myTabBarController.viewControllers = viewControllerArray; 

在我DisplayMarketViewController.m

self.tabBarItem.title = @"Tab1"; 
UIImage *image = [UIImage imageNamed:@"1.png"]; 
self.tabBarItem.image =image; 

和DisplayDifferenceMarketViewController.m

self.tabBarItem.title = @"Tab2"; 
UIImage *image = [UIImage imageNamed:@"2.png"]; 
self.tabBarItem.image =image; 

但是直到标签项被点击才显示Tab2。我该如何解决这个问题？

Answer 1

您的DisplayDifferenceMarketViewController未被初始化，直到通过点击标签栏来访问它。因此，更改选项卡标题的代码在您访问它之前不会执行。

简单地把所有的TabBar相关的代码之外的视图控制器在标签栏，用你的标签条形码，像这样的休息：

NSMutableArray *viewControllerArray = [[NSMutableArray alloc]initWithCapacity:2]; 

DisplayMarketViewController *displayMarketViewController = [[DisplayMarketViewController alloc]init];  
[viewControllerArray addObject:displayMarketViewController]; 
[displayMarketViewController release]; 

DisplayDifferenceMarketViewController *displayDifferenceMarketViewController = [[DisplayDifferenceMarketViewController alloc]init]; 
[viewControllerArray addObject:displayDifferenceMarketViewController]; 
[displayDifferenceMarketViewController release]; 
myTabBarController.viewControllers = viewControllerArray; 

[viewControllerArray objectAtIndex:0].tabBarItem.title = @"Tab1"; 
UIImage *image = [UIImage imageNamed:@"1.png"]; 
[viewControllerArray objectAtIndex:0].tabBarItem.image =image; 

[viewControllerArray objectAtIndex:1].tabBarItem.title = @"Tab2"; 
UIImage *image = [UIImage imageNamed:@"2.png"]; 
[viewControllerArray objectAtIndex:1].tabBarItem.image =image;