UITabBar

• 基本初始化
• tabBar 颜色与背景
• item 颜色与背景
• item 布局
• 当前 item
• 方法
• 代理 UITabBarDelegate

UITabBar : UIView
本身就是个 View，只是经常放在 TabBarController 中，单独也可以拿出来使用；

基本初始化

    self.tabbar = [[UITabBar alloc] initWithFrame:CGRectMake(20, 200, 300, 40)];
    [self.view addSubview:self.tabbar];

    UITabBarItem *barItem0 = [[UITabBarItem alloc] initWithTitle:@"111" image:[UIImage imageNamed:@"tab_0_normal"] selectedImage:[UIImage imageNamed:@"tab_0_selected"]];
    UITabBarItem *barItem1 = [[UITabBarItem alloc] initWithTitle:@"222" image:[UIImage imageNamed:@"tab_1_normal"] selectedImage:[UIImage imageNamed:@"tab_1_selected"]];
    self.tabbar.items = @[barItem0 ,barItem1];

tabBar 颜色与背景

    self.tabbar.translucent = YES;// 模糊处理
    self.tabbar.barStyle = UIBarStyleBlack;// 默认 2 选一
    self.tabbar.barTintColor = [UIColor yellowColor];// 背景颜色
    self.tabbar.backgroundImage = [UIImage imageNamed:@"backgroundImage"];// 背景图片
    self.tabbar.shadowImage = [UIImage imageNamed:@"shadowImage"];// 阴影图片，还必须与 backgroundImage 同时设置，不然设置无效，并使用默认颜色

item 颜色与背景

    self.tabbar.tintColor = [UIColor redColor];// 一般用图片原色，并不喜欢用这个 tintColor
    self.tabbar.unselectedItemTintColor = [UIColor blueColor];// iOS 10，且同上
    self.tabbar.selectionIndicatorImage = [UIImage imageNamed:@"icon"];// 选中 item 的背景

item 布局

    self.tabbar.itemPositioning = UITabBarItemPositioningAutomatic;// 填充方式
    self.tabbar.itemWidth = 50;
    self.tabbar.itemSpacing = 20;

当前 item

UITabBarItem 可以继续深入看

    UITabBarItem *item = self.tabbar.selectedItem；

方法

    [self.tabbar setItems:self.arr];    

• 编辑相关

    [self.tabbar beginCustomizingItems:self.arr];
    [self.tabbar endCustomizingAnimated:YES];

    BOOL custom = self.tabbar.isCustomizing;// 虽然是属性，也放这里了

代理 UITabBarDelegate

• 点击

- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item {
    NSLog(@"didSelectItem");
}

• 编辑，真心没见过有这种 APP

- (void)tabBar:(UITabBar *)tabBar willBeginCustomizingItems:(NSArray<UITabBarItem *> *)items {
    NSLog(@"willBeginCustomizingItems");
}

- (void)tabBar:(UITabBar *)tabBar didBeginCustomizingItems:(NSArray<UITabBarItem *> *)items {
    NSLog(@"didBeginCustomizingItems");
}

- (void)tabBar:(UITabBar *)tabBar willEndCustomizingItems:(NSArray<UITabBarItem *> *)items changed:(BOOL)changed {
    NSLog(@"willEndCustomizingItems");
}

- (void)tabBar:(UITabBar *)tabBar didEndCustomizingItems:(NSArray<UITabBarItem *> *)items changed:(BOOL)changed {
    NSLog(@"didEndCustomizingItems");
}