image scaling for UITabBar background image

问题

I've created UITabBarController in my application.

Then in viewDidLoad() I want to change UITabBar background image. Here is the code I'm trying to make it works:

class MainTabBarController: UITabBarController {

    override func viewDidLoad() {
        super.viewDidLoad()

        UITabBar.appearance().translucent = false
        UITabBar.appearance().backgroundColor = UIColor.clearColor()
        UITabBar.appearance().backgroundImage = UIImage(named: "tabbar_background")
        UITabBar.appearance().contentMode = .ScaleAspectFit
    }
}

But the result isn't correct (image). Can someone help me to make it fill the entire tabbar frame?

回答1:

Try resizing the image to the tab bar size. Or Add an imageView to the tabBar as subview, and then use the image in that imageView.

Subclass the TabBarController and add imageview there:

var bgView: UIImageView = UIImageView(image: UIImage(named: "tabBarBackground.png"))
bgView.frame = CGRectMake(0, 420, 320, 60)//you might need to modify this frame to your tabbar frame
self.view.addSubview(bgView)

回答2:

I solved this problem using clipsToBounds.
Here are my example:

let tabBar = self.tabBar
tabBar.backgroundImage = UIImage()
tabBar.clipsToBounds = true

This work perfectly on iPhone X

回答3:

Here is code for a custom translucent tab bar image with custom icons. You will need to refer directly to the tab bar via a variable.

Swift 3

private func setupTabBar() {
    print ("Setting up the Tab Bar and Items")

    tabBarView.clipsToBounds = true
    tabBarView.backgroundImage = UIImage()

    let bgView: UIImageView = UIImageView(image: #imageLiteral(resourceName: "TabBarBackground"))
    bgView.frame = tabBarView.bounds
    tabBarView.addSubview(bgView)

    tabBarView.tintColor = UIColor.white
    UITabBar.appearance().tintColor = UIColor.gray
    UITabBarItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName : UIColor.white], for: .normal)
    UITabBarItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName : UIColor.gray], for: .selected)

    tabBarLimitsItemView.image      = #imageLiteral(resourceName: "TabIconLimits").withRenderingMode(UIImageRenderingMode.alwaysOriginal)
    tabBarControlsItemView.image    = #imageLiteral(resourceName: "TabIconControls").withRenderingMode(UIImageRenderingMode.alwaysOriginal)
    tabBarPayRulesItemView.image    = #imageLiteral(resourceName: "TabIconPayRules").withRenderingMode(UIImageRenderingMode.alwaysOriginal)
    tabBarSettingsItemView.image    = #imageLiteral(resourceName: "TabIconSettings").withRenderingMode(UIImageRenderingMode.alwaysOriginal)
}

回答4:

This works for me in swift 3

class MyTabBarController: UITabBarController, UINavigationControllerDelegate {

override func viewDidLoad() {
    super.viewDidLoad()

    let backgroundImage = UIImageView(image: UIImage(named: "gray background"))
    backgroundImage.frame = backgroundImage.bounds
    self.view.addSubview(backgroundImage)


}

来源：https://stackoverflow.com/questions/34180293/image-scaling-for-uitabbar-background-image

标签

ios

swift

background

uitabbar