本篇主要对项目中适配iOS13 暗黑模式 TabBarItem图标更换的总结。方便日后复习。

一.暗黑模式下只有让unselectTabbarItem图标发生改变

操作方式：
1.先将一种模式下的unselectTabbarItem图标拉进Assets.xcassets中
2.选中图片属性的Appearances设置为Any,Dark，将另外一种对应模式下的图片放到对应位置
3.我们直接在创建UITabarBarItem的时候调用Assets.xcassets中图片的名称
4.操作如下图：

只有未选中图片切换暗黑模式.png

5.代码如下：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    tabbar = [[UITabBarController alloc]init];
    //情况1:暗黑模式切换中，只有unselectTabbarItem变化
//    [self case1_initialVC];
    //情况2:暗黑模式切换中，unselectTabbarItem跟selectTabbarItem 都需要变化
    [self case2_initialVC];
    
    self.window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];
    self.window.rootViewController = tabbar;
    [self.window makeKeyAndVisible];
    return YES;
}

//情况1
-(void)case1_initialVC {
    self.titleS = @[@"vc1",@"vc2",@"vc3",@"vc4"];
    self.normalImgS = @[@"tabbar_1_normal",@"tabbar_2_normal",@"tabbar_3_normal",@"tabbar_4_normal"];
    self.selectImgS = @[@"tabbar_1_select",@"tabbar_2_select",@"tabbar_3_select",@"tabbar_4_select"];
    oneVc = [ViewController new];
    [self addOneChildVC:oneVc title:self.titleS[0] normalImage:self.normalImgS[0] selectImage:self.selectImgS[0]];
    twoVc = [ViewController new];
    [self addOneChildVC:twoVc title:self.titleS[1] normalImage:self.normalImgS[1] selectImage:self.selectImgS[1]];
    threeVc = [ViewController new];
    [self addOneChildVC:threeVc title:self.titleS[2] normalImage:self.normalImgS[2] selectImage:self.selectImgS[2]];
    fourVc = [ViewController new];
    [self addOneChildVC:fourVc title:self.titleS[3] normalImage:self.normalImgS[3] selectImage:self.selectImgS[3]];
    
    
}

-(void)addOneChildVC:(UIViewController *)subVC title:(NSString *)title normalImage:(NSString *)normalStr selectImage:(NSString *)selectStr {
    subVC.tabBarItem.title = title;
    subVC.tabBarItem.image = [[UIImage imageNamed:normalStr] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    subVC.tabBarItem.selectedImage = [[UIImage imageNamed:selectStr] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    
    UINavigationController *navc = [[UINavigationController alloc]initWithRootViewController:subVC];
    navc.navigationBar.tintColor = [UIColor ios_13LigthColor:[UIColor redColor] darkColor:[UIColor whiteColor]];
    navc.navigationItem.title = title;
    [tabbar addChildViewController:navc];
    if (@available(iOS 13.0, *)) {
        [UITabBar appearance].barTintColor = [UIColor ios_13LigthColor:[UIColor whiteColor] darkColor:[UIColor blackColor]];
        navc.navigationBar.barTintColor = [UIColor ios_13LigthColor:[UIColor blueColor] darkColor:[UIColor redColor]];
        
        [subVC.tabBarItem setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor ios_13LigthColor:[UIColor redColor] darkColor:[UIColor whiteColor]]} forState:UIControlStateSelected];
        [subVC.tabBarItem setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor ios_13LigthColor:[UIColor blueColor] darkColor:[UIColor whiteColor]]} forState:UIControlStateNormal];
        tabbar.tabBar.backgroundColor = [UIColor ios_13LigthColor:[UIColor whiteColor] darkColor:[UIColor blackColor]];
        tabbar.tabBar.barTintColor = [UIColor ios_13LigthColor:[UIColor whiteColor] darkColor:[UIColor blackColor]];
        

    }
}

6.效果图如下：

日间模式.png

夜间模式.png

7.注意点：

a.即使将selectTabbarItem图标的Appearances设置为Any,Dark，将另外一种对应模式下的图片放到对应位置，切换暗黑模式也不会起作用
b.程序一旦重新启动，tabbarItem图标会根据暗黑模式正确显示

二.暗黑模式下TabbarItem图标均发生改变

操作方式：
1.我们在工程中导入两套图片（夜间模式和日间模式）
2.按照正常的创建方式创建TabbarItem图标
3.根据UITraitCollection.currentTraitCollection.userInterfaceStyle == UIUserInterfaceStyleDark 设置对应的图片
4.当切换模式的时候我们需要重新给TabbarItem重新一下添加image，因为tabbar用的系统类UITabBarController,如果想要监听模式改变，我们创建了一个分类就好，即UITabBarController+iOS13_DartModel
5.代码如下：

//情况2
-(void)case2_initialVC {
     self.titleS = @[@"vc1",@"vc2",@"vc3",@"vc4"];
    //日间模式
     self.normalImgS = @[@"tabbar_news_normal_2",@"tabbar_video_normal_2",@"tabbar_icourse_normal_2",@"tabbar_mine_normal_2"];
     self.selectImgS = @[@"tabbar_news_select_2",@"tabbar_video_select_2",@"tabbar_icourse_select_2",@"tabbar_mine_select_2"];
    //夜间模式
    self.normalDartImgS = @[@"tabbar_news_normal_1",@"tabbar_video_normal_1",@"tabbar_icourse_normal_1",@"tabbar_mine_normal_1"];
    self.selectDartImgS = @[@"tabbar_news_select_1",@"tabbar_video_select_1",@"tabbar_icourse_select_1",@"tabbar_mine_select_1"];
    oneVc = [ViewController new];
    twoVc = [ViewController new];
    threeVc = [ViewController new];
    fourVc = [ViewController new];
    
    if (UITraitCollection.currentTraitCollection.userInterfaceStyle == UIUserInterfaceStyleDark) {//夜间模式
        
        [self addOneChildVC:oneVc title:self.titleS[0] normalImage:self.normalDartImgS[0] selectImage:self.selectDartImgS[0]];
       
        [self addOneChildVC:twoVc title:self.titleS[1] normalImage:self.normalDartImgS[1] selectImage:self.selectDartImgS[1]];
        
        [self addOneChildVC:threeVc title:self.titleS[2] normalImage:self.normalDartImgS[2] selectImage:self.selectDartImgS[2]];
        
        [self addOneChildVC:fourVc title:self.titleS[3] normalImage:self.normalDartImgS[3] selectImage:self.selectDartImgS[3]];
    } else {
        [self addOneChildVC:oneVc title:self.titleS[0] normalImage:self.normalImgS[0] selectImage:self.selectImgS[0]];
        
         [self addOneChildVC:twoVc title:self.titleS[1] normalImage:self.normalImgS[1] selectImage:self.selectImgS[1]];
         
         [self addOneChildVC:threeVc title:self.titleS[2] normalImage:self.normalImgS[2] selectImage:self.selectImgS[2]];
         
         [self addOneChildVC:fourVc title:self.titleS[3] normalImage:self.normalImgS[3] selectImage:self.selectImgS[3]];
    }
    
}

UITabBarController+iOS13_DartModel 分类如下：

@implementation UITabBarController (iOS13_DartModel)
-(void)traitCollectionDidChange:(UITraitCollection *)previousTraitCollection {
    if (@available(iOS 13.0, *)){
        AppDelegate *delegate = (AppDelegate *)[UIApplication sharedApplication].delegate;
        UITabBarController *tabbar = (UITabBarController *)[UIApplication sharedApplication].keyWindow.rootViewController;
        NSArray *navcs = tabbar.viewControllers;
        
        if (previousTraitCollection.userInterfaceStyle == UIUserInterfaceStyleDark) {
            int i = 0;
            for (UINavigationController *navc in navcs) {
                UIViewController *vc = (UIViewController *)([navc.viewControllers firstObject]);
                vc.tabBarItem.selectedImage = [[UIImage imageNamed:delegate.selectImgS[i]] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
                vc.tabBarItem.image = [[UIImage imageNamed:delegate.normalImgS[i]] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
                i++;
            }
            [[UITabBar appearance] setTintColor:[UIColor whiteColor]];
           
        } else {
           int i = 0;
            for (UINavigationController *navc in navcs) {
                UIViewController *vc = (UIViewController *)([navc.viewControllers firstObject]);
                vc.tabBarItem.selectedImage = [[UIImage imageNamed:delegate.selectDartImgS[i]] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
                vc.tabBarItem.image = [[UIImage imageNamed:delegate.normalDartImgS[i]] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
                i++;
            }
            [[UITabBar appearance] setTintColor:[UIColor blackColor]];
        }
    }
}
@end

6.效果图如下：

日间模式.png

夜间模式.png

7.注意点：

demo运行的时候，如果想验证情况1，需要把UITabBarController+iOS13_DartModel分类去掉；
如果想验证情况2，需要把UITabBarController+iOS13_DartModel分类添加

demo地址：https://github.com/sisios/DartMode_TabBarItemImage.git
本篇学习先记录到此，感谢阅读，如有错误，不吝赐教。