ios - 分段控制更改时更改 View Controller

Question

这个问题快把我逼疯了。当用户更改分段控件的选定“选项卡”时，我试图更改 viewController。我花了几个小时进行研究，但未能找到有效的答案或通过 Storyboard完成的答案。

这真的很困扰我，因为设置选项卡应用程序是如此简单，但是尝试像选项卡应用程序一样使用分段控件就是行不通。我已经知道如何检测在分段控件中选择了哪个索引。我怎样才能做到这一点？

非常感谢。

Answer 1

注意:答案更新为 iOS 5+ 的 View Controller 包含代码，包括 @interface 部分

在我的一个应用程序中，我在导航栏中有一个带有段控件的 View Controller ，单击“选项卡”切换 View Controller 。基本思想是拥有一个 View Controller 数组，并使用段索引(和 indexDidChangeForSegmentedControl IBAction)在它们之间切换。

我的应用程序中的示例代码(iOS 5 或更高版本)(这是针对 2 个 View Controller 的，但它很容易扩展到多个 View Controller )；代码比 iOS 4 稍长，但会保持对象图的完整性。此外，它使用 ARC:

@interface MyViewController ()
// Segmented control to switch view controllers
@property (weak, nonatomic) IBOutlet UISegmentedControl *switchViewControllers;

// Array of view controllers to switch between
@property (nonatomic, copy) NSArray *allViewControllers;

// Currently selected view controller
@property (nonatomic, strong) UIViewController *currentViewController;
@end

@implementation UpdateScoreViewController
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];

    // Create the score view controller
    ViewControllerA *vcA = [self.storyboard instantiateViewControllerWithIdentifier:@"ViewControllerA"];

    // Create the penalty view controller
    ViewControllerB *vcB = [self.storyboard instantiateViewControllerWithIdentifier:@"ViewControllerB"];

    // Add A and B view controllers to the array
    self.allViewControllers = [[NSArray alloc] initWithObjects:vcA, vcB, nil];

    // Ensure a view controller is loaded
    self.switchViewControllers.selectedSegmentIndex = 0;
    [self cycleFromViewController:self.currentViewController toViewController:[self.allViewControllers objectAtIndex:self.switchViewControllers.selectedSegmentIndex]];
}

#pragma mark - View controller switching and saving

- (void)cycleFromViewController:(UIViewController*)oldVC toViewController:(UIViewController*)newVC {

    // Do nothing if we are attempting to swap to the same view controller
    if (newVC == oldVC) return;

    // Check the newVC is non-nil otherwise expect a crash: NSInvalidArgumentException
    if (newVC) {

        // Set the new view controller frame (in this case to be the size of the available screen bounds)
        // Calulate any other frame animations here (e.g. for the oldVC)
        newVC.view.frame = CGRectMake(CGRectGetMinX(self.view.bounds), CGRectGetMinY(self.view.bounds), CGRectGetWidth(self.view.bounds), CGRectGetHeight(self.view.bounds));

        // Check the oldVC is non-nil otherwise expect a crash: NSInvalidArgumentException
        if (oldVC) {

            // Start both the view controller transitions
            [oldVC willMoveToParentViewController:nil];
            [self addChildViewController:newVC];

            // Swap the view controllers
            // No frame animations in this code but these would go in the animations block
            [self transitionFromViewController:oldVC
                              toViewController:newVC
                                      duration:0.25
                                       options:UIViewAnimationOptionLayoutSubviews
                                    animations:^{}
                                    completion:^(BOOL finished) {
                                        // Finish both the view controller transitions
                                        [oldVC removeFromParentViewController];
                                        [newVC didMoveToParentViewController:self];
                                        // Store a reference to the current controller
                                        self.currentViewController = newVC;
                                    }];

        } else {

            // Otherwise we are adding a view controller for the first time
            // Start the view controller transition
            [self addChildViewController:newVC];

            // Add the new view controller view to the ciew hierarchy
            [self.view addSubview:newVC.view];

            // End the view controller transition
            [newVC didMoveToParentViewController:self];

            // Store a reference to the current controller
            self.currentViewController = newVC;
        }
    }
}

- (IBAction)indexDidChangeForSegmentedControl:(UISegmentedControl *)sender {

    NSUInteger index = sender.selectedSegmentIndex;

    if (UISegmentedControlNoSegment != index) {
        UIViewController *incomingViewController = [self.allViewControllers objectAtIndex:index];
        [self cycleFromViewController:self.currentViewController toViewController:incomingViewController];
    }

}
@end

原始示例(iOS 4 或更早版本):

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];

    // Create the score view controller
    AddHandScoreViewController *score = [self.storyboard instantiateViewControllerWithIdentifier:@"AddHandScore"];

    // Create the penalty view controller
    AddHandPenaltyViewController *penalty = [self.storyboard instantiateViewControllerWithIdentifier:@"AddHandPenalty"];

    // Add Score and Penalty view controllers to the array
    self.allViewControllers = [[NSArray alloc] initWithObjects:score, penalty, nil];

    // Ensure the Score controller is loaded
    self.switchViewControllers.selectedSegmentIndex = 0;
    [self switchToController:[self.allViewControllers objectAtIndex:self.switchViewControllers.selectedSegmentIndex]];
}

#pragma mark - View controller switching and saving

- (void)switchToController:(UIViewController *)newVC
{
    if (newVC) {
        // Do nothing if we are in the same controller
        if (newVC == self.currentViewController) return;

        // Remove the current controller if we are loaded and shown
        if([self.currentViewController isViewLoaded]) [self.currentViewController.view removeFromSuperview];

        // Resize the new view controller
        newVC.view.frame = CGRectMake(CGRectGetMinX(self.view.bounds), CGRectGetMinY(self.view.bounds), CGRectGetWidth(self.view.bounds), CGRectGetHeight(self.view.bounds));

        // Add the new controller
        [self.view addSubview:newVC.view];

        // Store a reference to the current controller
        self.currentViewController = newVC;
    }
}

- (IBAction)indexDidChangeForSegmentedControl:(UISegmentedControl *)sender {

    NSUInteger index = sender.selectedSegmentIndex;

    if (UISegmentedControlNoSegment != index) {
        UIViewController *incomingViewController = [self.allViewControllers objectAtIndex:index];
        [self switchToController:incomingViewController];
    }

}