Swift – how to change font size and font name of uisegmentedcontrol programmatically on swift

I ran into the same issue. This code sets the font size for the entire segmented control. Something similar might work for setting the font type. Note that this is only available for iOS5+

Obj C:

UIFont *font = [UIFont boldSystemFontOfSize:12.0f];
NSDictionary *attributes = [NSDictionary dictionaryWithObject:font
                                                       forKey:NSFontAttributeName];
[segmentedControl setTitleTextAttributes:attributes 
                                forState:UIControlStateNormal];

EDIT: UITextAttributeFont has been deprecated - use NSFontAttributeName instead.

EDIT #2: For Swift 4 NSFontAttributeName has been changed to NSAttributedStringKey.font.

Swift 5:

let font = UIFont.systemFont(ofSize: 16)
segmentedControl.setTitleTextAttributes([NSAttributedString.Key.font: font], for: .normal)

Swift 4:

let font = UIFont.systemFont(ofSize: 16)
segmentedControl.setTitleTextAttributes([NSAttributedStringKey.font: font],
                                        for: .normal)

Swift 3:

let font = UIFont.systemFont(ofSize: 16)
segmentedControl.setTitleTextAttributes([NSFontAttributeName: font],
                                        for: .normal)

Swift 2.2:

let font = UIFont.systemFontOfSize(16)
segmentedControl.setTitleTextAttributes([NSFontAttributeName: font], 
    forState: UIControlState.Normal)

Thanks to the Swift implementations from @audrey-gordeev

1. Set the UIViewControllerBasedStatusBarAppearance to YES in the .plist file.

2. In the viewDidLoad do a [self setNeedsStatusBarAppearanceUpdate];

3. Add the following method:

   - (UIStatusBarStyle)preferredStatusBarStyle
   { 
       return UIStatusBarStyleLightContent; 
   }
   

Note: This does not work for controllers inside UINavigationController, please see Tyson's comment below :)

Swift 3 - This will work controllers inside UINavigationController. Add this code inside your controller.

// Preferred status bar style lightContent to use on dark background.
// Swift 3
override var preferredStatusBarStyle: UIStatusBarStyle {
    return .lightContent
}

Swift 5 and SwiftUI

For SwiftUI create a new swift file called HostingController.swift

import Foundation
import UIKit
import SwiftUI

class HostingController: UIHostingController<ContentView> {
    override var preferredStatusBarStyle: UIStatusBarStyle {
        return .lightContent
    }
}

Then change the following lines of code in the SceneDelegate.swift

window.rootViewController = UIHostingController(rootView: ContentView())

to

window.rootViewController = HostingController(rootView: ContentView())