TabBarController didSelectViewController无法正常工作

Question

我知道这是一个非常重复的话题,但我无法理解它.

MainTab.h:

#import <UIKit/UIKit.h>

@interface MainTab : UITabBarController<UITabBarControllerDelegate, UITabBarDelegate> {

     IBOutlet UITabBarController *tabController;

}

@property (nonatomic,retain) IBOutlet UITabBarController *tabController;

@end

MainTab.m

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    NSLog(@"main tab"); 
    [super viewDidLoad];

    self.tabBarController.delegate = (id)self;
    [self setDelegate:self];

    // Do any additional setup after loading the view.
}

- (void)viewDidUnload
{
    [super viewDidUnload];
    // Release any retained subviews of the main view.
}


-(void) tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
{

    NSLog(@"selected %d",tabBarController.selectedIndex);

}

我找不到我错过的东西,任何帮助将不胜感激.

现在我尝试将其链接到MainStoryBoard:

但它不起作用,有什么联系？

Answer 1

根据您的@interface(和您的后续屏幕快照),MainTab是UITabBarController,所以以下行:

self.tabBarController.delegate = (id)self;

应该只是:

self.delegate = self;

您不希望tabBarController在UITabBarController本身中使用属性,也不想使用self.tabBarController语法.如果您尝试从其中一个子控制器引用标签栏控制器,则只使用该语法.在标签栏控制器本身时,只需参考self.

因此,如果MainBar定义为:

//  MainBar.h

#import <UIKit/UIKit.h>

@interface MainBar : UITabBarController

@end

和

//  MainBar.m

#import "MainBar.h"

@interface MainBar () <UITabBarControllerDelegate>

@end

@implementation MainBar

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.delegate = self;
}

-(void) tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
{
    NSLog(@"selected %d",tabBarController.selectedIndex);
}

@end

并且不要忘记设置标签栏控制器的类:

连接检查员(我没有碰过的东西)看起来像: