UI: 使用 UITabBarController 显示多视图控制器

假设有两个视图控制器,它们的分别为 FirstViewController 和 SecondViewControlller。 现在到 app delegate 中定义视图控制器和标签栏。代码如下: 

 .h:

#import <UIKit/UIKit.h>
#import "FirstViewController.h"
#import "SecondViewController.h"

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;
@property (nonatomic ,strong) FirstViewController *firstViewController;
@property (nonatomic ,strong) SecondViewController *secondViewController;
@property (nonatomic ,strong) UITabBarController *tabBarControllser;
@end

.m:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    self.window = [[UIWindow alloc]initWithFrame:[[UIScreen mainScreen]bounds]];
    [self.window makeKeyAndVisible];
    [self createViewControllers01];
    return YES;
}

-(void)createViewControllers01{
    //1
    FirstViewController *firstVC = [[FirstViewController alloc]init];
    UINavigationController *navfirst = [[UINavigationController alloc]initWithRootViewController:firstVC];
    //2
    SecondViewController *secondVC = [[SecondViewController alloc]init];
    UINavigationController *navSecond = [[UINavigationController alloc]initWithRootViewController:secondVC];
    
    //UINavigationController控制器数组
    NSArray *arrayNav = [[NSArray alloc]initWithObjects:navfirst,navSecond, nil];
/*************************/
    UITabBarController *tbc = [[UITabBarController alloc]init];
    tbc.viewControllers = arrayNav;
    self.window.rootViewController = tbc;
}

如果视图多的时候,另一种方法:

- (void)createViewControllers02{
    //视图数组
    NSArray *arrayVC = [NSArray arrayWithObjects:@"firstVC",@"secondVC", nil];
    //每个视图对应的颜色数组
    NSArray *colorVC = [NSArray arrayWithObjects:[UIColor redColor],[UIColor blackColor], nil];
    //每个视图对应的tabbar图片数组
    NSArray *tabBarImageTitle = [NSArray arrayWithObjects:@"tabbar_first",@"tabbar_second", nil];
    //每个视图对用的tabbar标题数组
    NSArray *tabbarTitle = [NSArray arrayWithObjects:@"一",@"二", nil];
    
    NSMutableArray *arrayTBC = [[NSMutableArray alloc]init];
    for (int i =0; i<arrayVC.count; i++) {
        //将字符串转换为某个抽象类
        Class cVC = NSClassFromString([arrayVC objectAtIndex:i]);
        //初始化后赋值给视图控制器对象
        UIViewController *vc = [[cVC alloc]init];
        //给视图控制器添加背景颜色
        vc.view.backgroundColor = [colorVC objectAtIndex:i];
        //初始化每个视图对应的tabBarItem并将其赋值给每个视图
        UITabBarItem *tabBarItem = [[UITabBarItem alloc]initWithTitle:[tabbarTitle objectAtIndex:i] image:[UIImage imageNamed:[tabBarImageTitle objectAtIndex:i]] tag:i+100];
        vc.tabBarItem = tabBarItem;
        //将每个视图加入视图控制器并存入数组
        UINavigationController *nav = [[UINavigationController alloc]initWithRootViewController:vc];
        [arrayTBC addObject:nav];
    }
    //初始化UITabBarController并对其赋值
    UITabBarController *tbc = [[UITabBarController alloc]init];
    tbc.viewControllers = arrayTBC;
}