將初始視圖控制器連接到選項卡視圖控制器

Question

我想將登錄場景用作初始視圖控制器並將其連接到選項卡視圖控制器。我不斷收到以下錯誤消息：

終止應用程序由於未捕獲的異常 'NSInvalidArgumentException'，原因： ' - [UIViewController中的TabBar]：無法識別的選擇發送到實例0x7fe85a560fd0'

// LogInViewController.h 
#import <UIKit/UIKit.h> 

@interface LogInViewController : UIViewController <UITextFieldDelegate> 
@property (weak, nonatomic) IBOutlet UITextField *txtUsername; 
@property (weak, nonatomic) IBOutlet UITextField *txtPassword; 

- (IBAction)sigininClicked:(id)sender; 

- (IBAction)backgroundTap:(id)sender; 
@end 


// AppDelegate.m 
// 

#import "AppDelegate.h" 

@interface AppDelegate() 

@end 

@implementation AppDelegate 

- (BOOL)application:(UIApplication *)application  didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 
{ 

// Assign tab bar item with titles 
UITabBarController *tabBarController = (UITabBarController *)self.window.rootViewController; 
UITabBar *tabBar = tabBarController.tabBar; 
UITabBarItem *tabBarItem1 = [tabBar.items objectAtIndex:0]; 
UITabBarItem *tabBarItem2 = [tabBar.items objectAtIndex:1]; 
UITabBarItem *tabBarItem3 = [tabBar.items objectAtIndex:2]; 
UITabBarItem *tabBarItem4 = [tabBar.items objectAtIndex:3]; 

tabBarItem1.title = @"Trucks"; 
tabBarItem2.title = @"Dashboard"; 
tabBarItem3.title = @"Map"; 
tabBarItem4.title = @"Settings"; 

[tabBarItem1 setFinishedSelectedImage:[UIImage imageNamed:@"iu.png"] 
      withFinishedUnselectedImage:[UIImage imageNamed:@"iu.png"]]; 
[tabBarItem2 setFinishedSelectedImage:[UIImage imageNamed:@"dashboard.png"] 
      withFinishedUnselectedImage:[UIImage imageNamed:@"dashboard.png"]]; 
[tabBarItem3 setFinishedSelectedImage:[UIImage imageNamed:@"globe.png"] 
      withFinishedUnselectedImage:[UIImage imageNamed:@"globe.png"]]; 
[tabBarItem4 setFinishedSelectedImage:[UIImage imageNamed:@"settings.png"] 
      withFinishedUnselectedImage:[UIImage imageNamed:@"settings.png"]]; 

return YES; 
} 

Answer 1

我我不是ios的專家，但這裏是我最近編程的方式（沒有故事板）在我的應用程序中。這是從我的appdelegate中提取的代碼，但它也應該用於您的目的。

在.h文件：

@interface AppDelegate : UIResponder <UIApplicationDelegate, UITabBarControllerDelegate> 
     @property (strong, nonatomic) UITabBarController *tabBarController; 
     @property (strong, nonatomic) UIWindow *window; 

在.m文件：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { 
    self.window = [[UIWindow alloc]initWithFrame:[[UIScreen mainScreen]bounds]]; 
    self.tabBarController = [[UITabBarController alloc] init]; 
    FirstViewController *firstvc = [[FirstViewController alloc] init]; 
    SecondViewController *secondvc = [[SecondViewController alloc] init]; 
    tabBarController.viewControllers = @[firstvc, secondvc]; 
    self.window.rootViewController = tabBarController; 
} 

編輯：

在我的FirstViewController和SecondViewController .m文件：

- (instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{ 
    self= [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; 

    if(self){ 
     self.tabBarItem.image = [UIImage imageNamed:@"img_vc1"]; 
     self.tabBarItem.title = @"My 1st View"; 
    } 
    return self; 
} 

Hope這有助於。