如何更改iPhone中Tabbar中选定的选项卡项？

Question

我已在视图控制器中以编程方式创建了选项卡栏。在我的应用程序中，最初显示选项卡栏，并且视图中有五个选项卡栏项目。使用选项卡栏，最初选择第一个选项卡项目。现在我想更改所选项目，例如最初选择第四个项目。（参见图片）
我该如何实现这一目标？

这是我的代码，

    tBar = [[UITabBarController alloc] init];

    first = [[first alloc] initWithNibName:@"first" bundle:nil];

    UINavigationController *navFirst = [[[UINavigationController alloc] initWithRootViewController:first] autorelease];

    second = [[second alloc] initWithNibName:@"second" bundle:nil];

    UINavigationController *navsecond = [[[UINavigationController alloc] initWithRootViewController:second] autorelease];

    third = [[third alloc] initWithNibName:@"third" bundle:nil];

   UINavigationController *navthird = [[[UINavigationController alloc] initWithRootViewController:third] autorelease];

   fourth = [[fourth alloc] initWithNibName:@"fourth" bundle:nil];

    UINavigationController *navfourth = [[[UINavigationController alloc] initWithRootViewController:fourth] autorelease];

   fifth = [[fifth alloc] initWithNibName:@"fifth" bundle:nil];

   UINavigationController *navfifth= [[[UINavigationController alloc] initWithRootViewController:fifth] autorelease];

   tBar.viewControllers = [NSArray arrayWithObjects:navFirst,navsecond, navthird, navfourth, navfifth,nil]; 

   [self.view addSubview:tBar.view];

   [self.navigationController pushViewController:tBar animated:NO];

请参见下图。我想要完全像这样，

图片 http://www.freeimagehosting.net/uploads/2798661c55.png

请指导我。

谢谢。

Answer 1

试试这个：

YourAppNameDelegate *appDelegate = (YourAppNameDelegate *)[[UIApplication sharedApplication] delegate];
[appDelegate tabBarController].selectedIndex = 3;

或者

tBar.selectedIndex = 3;

Answer 2

如果您想以编程方式从一个项目更改为另一个项目，您也可以这样做：

[self parentViewController].yourTabBar.selectedIndex = 3;

我希望这对某人有帮助