What are the correct dimensions for a custom tab bar item background image?

Question

So I have a .png that\'s 428x176 px:

I want to use it as a tab bar background image for when an item is in the selected state. The problem is t

Answer 1

Making my answer for this question how to make UITabBar selection indicator image fill the whole space? as reference:

Subclass the UITabBarController

It works for multiple devices even with rotation.

Notes:

1. Make your images' rendering mode as Original.

2. Assign this class below to your UITabBarController in your Storyboard or as your base class if you're doing your screen programmatically.

   //
   //  BaseTabBarController.swift
   //  MyApp
   //
   //  Created by DRC on 1/27/17.
   //  Copyright © 2017 PrettyITGirl. All rights reserved.
   //
   
   import UIKit
   
   class BaseTabBarController: UITabBarController {
   
       let numberOfTabs: CGFloat = 4
       let tabBarHeight: CGFloat = 60
   
       override func viewWillAppear(_ animated: Bool) {
           super.viewWillAppear(animated)
   
           updateSelectionIndicatorImage()
       }
   
       override func viewWillLayoutSubviews() {
           super.viewWillLayoutSubviews()
   
           updateSelectionIndicatorImage()
       }
   
       func updateSelectionIndicatorImage() {
           let width = tabBar.bounds.width
           var selectionImage = UIImage(named:"myimage.png")
           let tabSize = CGSize(width: width/numberOfTabs, height: tabBarHeight)
   
           UIGraphicsBeginImageContext(tabSize)
           selectionImage?.draw(in: CGRect(x: 0, y: 0, width: tabSize.width, height: tabSize.height))
           selectionImage = UIGraphicsGetImageFromCurrentImageContext()
           UIGraphicsEndImageContext()
   
           tabBar.selectionIndicatorImage = selectionImage
       }
   
   }