UITabBarController（二）

本文简单介绍两个使用示例及代码。

示例一

代码方式 创建 UITabBarController , 在 UITabBarController 控件上放两个视图控制器。

Demo:

文档组织结构

实现步骤

• 1️⃣ 新建两个父类为 UIViewController 的带 xib 的视图控制器，MainViewController 和 LoginViewController

• 2️⃣ AppDelegate.h:

#import <UIKit/UIKit.h>
// 导入创建的视图控制器头文件
#import "MainViewController.h"
#import "LoginViewController.h"

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;

// 添加选项卡控制器属性，用来展示组合并展示创建的两个视图控制器
@property (strong, nonatomic) UITabBarController *tabBarController;

@end

• 3️⃣ AppDelegate.m

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

    // 创建 Window
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

    // 实例化视图控制器对象
    UIViewController *mainViewController = [[MainViewController alloc] initWithNibName:@"MainViewController" bundle:nil];
    UIViewController *loginViewController = [[LoginViewController alloc] initWithNibName:@"LoginViewController" bundle:nil];

    // 初始化选项卡视图控制器
    self.tabBarController = [[UITabBarController alloc] init];

    // 将两个视图控制器以数组的方法指定给选项卡视图控制器
    NSArray *viewControllerArrays = [NSArray arrayWithObjects:mainViewController,loginViewController, nil];
    self.tabBarController.viewControllers = viewControllerArrays;

    // 设置选项卡视图控制器为当前窗口的根视图控制器
    self.window.rootViewController  = _tabBarController;

    self.window.backgroundColor = [UIColor whiteColor];
    // 设置 Window 为主窗口并显示
    [self.window makeKeyAndVisible];

    return YES;
}

• 4️⃣ 设置每个视图控制器标签的标题和图标

MainViewController.m

  - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        self.title = @"主页";
        self.tabBarItem.image = [UIImage imageNamed:@"1"];
        [self.view setBackgroundColor:[UIColor whiteColor]];
    }
    return self;
}

LoginViewController.m

  - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        self.title = @"登录";
        self.tabBarItem.image = [UIImage imageNamed:@"4"];
        [self.view setBackgroundColor:backgroundColor];
    }
    return self;
}

• 完成。

示例二：自定义 UITabBarController 子类对象：

- (instancetype)init {
    self = [super init];
    if (self) {
        // 设置背景颜色和大小
        self.view.backgroundColor = COLOR_BACKGROUND;
        self.view.frame = CGRectMake(0, 0, kScreenWidth, kScreenHeight);

        [self setViewControllers];
    }
    return self;
}

/*
 * 视图堆栈结构：
 * UITabBarController - UINavigationController - UIViewController （首页）
 *                    - UINavigationController - UIViewController （资讯）
 *                    - UINavigationController - UIViewController （我的）
 *
 */
- (void)setViewControllers {
    // 首页 TabBar
    UIViewController *mainViewController = [self renderTabBarItem:[[HQLMainViewController alloc] init] title:@"首页" imageNamed:@"tab_home_normal" selectedImageNamed:@"tab_home_selected"];
    HQLNavigationController *mainNavigationController = [[HQLNavigationController alloc] initWithRootViewController:mainViewController];

    // 资讯 TabBar
    UIViewController *secondViewController = [self renderTabBarItem:[[HQLSecondViewController alloc] init] title:@"资讯" imageNamed:@"tab_news_normal" selectedImageNamed:@"tab_news_selected"];
    HQLNavigationController *secondNavigationController = [[HQLNavigationController alloc] initWithRootViewController:secondViewController];

    // 我的 Tabbar
    UIViewController *thirdViewController = [self renderTabBarItem:[[HQLThirdViewController alloc] initWithStyle:UITableViewStyleGrouped] title:@"我的" imageNamed:@"tab_mine_normal" selectedImageNamed:@"tab_mine_selected"];
    HQLNavigationController *thirdNavigationController = [[HQLNavigationController alloc] initWithRootViewController:thirdViewController];

    self.viewControllers = @[mainNavigationController,secondNavigationController,thirdNavigationController];
}

- (UIViewController *)renderTabBarItem:(UIViewController *)viewController
                                 title:(NSString *)title
                            imageNamed:(NSString *)normalImgName
                    selectedImageNamed:(NSString *)selectedImgName {

    viewController.title = title;

    UIImage *normalImage = [[UIImage imageNamed:normalImgName] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    UIImage *selectedImage = [[UIImage imageNamed:selectedImgName] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    viewController.tabBarItem = [[UITabBarItem alloc] initWithTitle:title image:normalImage selectedImage:selectedImage];
    [viewController.tabBarItem setTitleTextAttributes:@{NSForegroundColorAttributeName: COLOR_THEME}
                                             forState:UIControlStateSelected];
    return viewController;
}