swift3.0中使用代碼添加選中圖片

        private lazy var imageNames = ["tabbar_home", "tabbar_message_center", "", "tabbar_discover", "tabbar_profile"]
        // 遍歷全部的item
        for i in 0..<tabBar.items!.count {
            // 2. 獲取item
            let item = tabBar.items![i]
            
            // 3. 若是下標爲2，則該item不能夠和用戶交互
            if i == 2 {
                item.isEnabled = false
                continue
            }
            // 4. 設置其餘item選中時候的圖片
            item.selectedImage = UIImage(named: imageNames[i] + "_highlighted")
            print("\(item.selectedImage)")
        }