How can I substitute the UITabBar of UITabBarController programmatically

Question

I need to use a subclass of the UITabBar for my project because of the following problem Why page Push animation Tabbar moving up in the iPhone X .

I do not use storyboards. How can this be done programmatically?

-- update --

My CustomTabBarController.swift file now looks like this:

import UIKit

@objc class customTabBarController: UITabBarController {
    override var tabBar: UITabBar {
        return customTabBar
    }
}

And my CustomTabBar.swift file looks like this:

import UIKit

class customTabBar: UITabBar {

    override var frame: CGRect {
        get {
            return super.frame
        }
        set {
            var tmp = newValue
            if let superview = superview, tmp.maxY !=
                superview.frame.height {
                tmp.origin.y = superview.frame.height - tmp.height
            }

            super.frame = tmp
        }
    }
}

But this gives me the following error:

Cannot convert return expression of type 'customTabBar.Type' to return type 'UITabBar'

Answer 1

You should create an instance of your custom tab bar and override the tabBar property inside your UITabBarController subclass with it.

class CustomTabBarController: UITabBarController {
    let customTabBar = CustomTabBar()

    override var tabBar: UITabBar {
        return customTabBar
    }
}    

Answer 2

通过在UITabBarController上使用setValue(:forKey:)在这个答案中给出了唯一有效的解决方案。

Answer 3

The reason you're getting the 'customTabBar.Type' error is because you're returning the name of your class which, against normal convention, is camel cased. You want to be returning an object - an instance of your class - instead.

import UIKit

@objc class customTabBarController: UITabBarController {
    let myCustomTabBar = customTabBar() // If we're writing conventional swift,
                                        // this should be CustomTabBar()
    
    override var tabBar: UITabBar {
        // Because your class name is customTabBar instead of CustomTabBar,
        // this is returning a TYPE instead of an OBJECT
        // return customTabBar

        // If you wanted to return a new version of a tab bar on every
        // get of this object, you'd use the following code which is similar to yours:
        // return customTabBar()

        // More likely, you want to return the SAME tabBar throughout this object's
        // lifecycle.
        return myCustomTabBar
    }
}