Set a default font for whole iOS app?

Question

I have a custom font I want to use for everything displaying text in my app, labels, text views etc.

Is there a way to set the default font (labels by default use SystemFont) for the whole app?

Answer 1

It seems to be possible in iOS 5 using the UIAppearance proxy.

 [[UILabel appearance] setFont:[UIFont fontWithName:@"YourFontName" size:17.0]];

That will set the font to be whatever your custom font is for all UILabels in your app. You'll need to repeat it for each control (UIButton, UILabel, etc.).

Remember you'll need to put the UIAppFonts value in your info.plist and include the name of the font you're including.

Answer 2

Swift 5

Base on Fábio Oliveira's answer (https://stackoverflow.com/a/23042694/2082851), I make my own swift 4.

In short, this extension exchanges default functions init(coder:), systemFont(ofSize:), boldSystemFont(ofSize:), italicSystemFont(ofSize:) with my custom methods.

Note that it's not fully implement, but you can exchange more methods base on my implementation.

import UIKit

struct AppFontName {
    static let regular = "CourierNewPSMT"
    static let bold = "CourierNewPS-BoldMT"
    static let italic = "CourierNewPS-ItalicMT"
}

extension UIFontDescriptor.AttributeName {
    static let nsctFontUIUsage = UIFontDescriptor.AttributeName(rawValue: "NSCTFontUIUsageAttribute")
}

extension UIFont {
    static var isOverrided: Bool = false

    @objc class func mySystemFont(ofSize size: CGFloat) -> UIFont {
        return UIFont(name: AppFontName.regular, size: size)!
    }

    @objc class func myBoldSystemFont(ofSize size: CGFloat) -> UIFont {
        return UIFont(name: AppFontName.bold, size: size)!
    }

    @objc class func myItalicSystemFont(ofSize size: CGFloat) -> UIFont {
        return UIFont(name: AppFontName.italic, size: size)!
    }

    @objc convenience init(myCoder aDecoder: NSCoder) {
        guard
            let fontDescriptor = aDecoder.decodeObject(forKey: "UIFontDescriptor") as? UIFontDescriptor,
            let fontAttribute = fontDescriptor.fontAttributes[.nsctFontUIUsage] as? String else {
                self.init(myCoder: aDecoder)
                return
        }
        var fontName = ""
        switch fontAttribute {
        case "CTFontRegularUsage":
            fontName = AppFontName.regular
        case "CTFontEmphasizedUsage", "CTFontBoldUsage":
            fontName = AppFontName.bold
        case "CTFontObliqueUsage":
            fontName = AppFontName.italic
        default:
            fontName = AppFontName.regular
        }
        self.init(name: fontName, size: fontDescriptor.pointSize)!
    }

    class func overrideInitialize() {
        guard self == UIFont.self, !isOverrided else { return }

        // Avoid method swizzling run twice and revert to original initialize function
        isOverrided = true

        if let systemFontMethod = class_getClassMethod(self, #selector(systemFont(ofSize:))),
            let mySystemFontMethod = class_getClassMethod(self, #selector(mySystemFont(ofSize:))) {
            method_exchangeImplementations(systemFontMethod, mySystemFontMethod)
        }

        if let boldSystemFontMethod = class_getClassMethod(self, #selector(boldSystemFont(ofSize:))),
            let myBoldSystemFontMethod = class_getClassMethod(self, #selector(myBoldSystemFont(ofSize:))) {
            method_exchangeImplementations(boldSystemFontMethod, myBoldSystemFontMethod)
        }

        if let italicSystemFontMethod = class_getClassMethod(self, #selector(italicSystemFont(ofSize:))),
            let myItalicSystemFontMethod = class_getClassMethod(self, #selector(myItalicSystemFont(ofSize:))) {
            method_exchangeImplementations(italicSystemFontMethod, myItalicSystemFontMethod)
        }

        if let initCoderMethod = class_getInstanceMethod(self, #selector(UIFontDescriptor.init(coder:))), // Trick to get over the lack of UIFont.init(coder:))
            let myInitCoderMethod = class_getInstanceMethod(self, #selector(UIFont.init(myCoder:))) {
            method_exchangeImplementations(initCoderMethod, myInitCoderMethod)
        }
    }
}


class AppDelegate: UIResponder, UIApplicationDelegate {
    // Avoid warning of Swift
    // Method 'initialize()' defines Objective-C class method 'initialize', which is not guaranteed to be invoked by Swift and will be disallowed in future versions
    override init() {
        super.init()
        UIFont.overrideInitialize()
    }
    ...
}

Answer 3

There is also another solution which will be to override systemFont.

Just create a category

UIFont+SystemFontOverride.h

#import <UIKit/UIKit.h>

@interface UIFont (SystemFontOverride)
@end

UIFont+SystemFontOverride.m

@implementation UIFont (SystemFontOverride)

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wobjc-protocol-method-implementation"

+ (UIFont *)boldSystemFontOfSize:(CGFloat)fontSize {
    return [UIFont fontWithName:@"fontName" size:fontSize];
}

+ (UIFont *)systemFontOfSize:(CGFloat)fontSize {
    return [UIFont fontWithName:@"fontName" size:fontSize];
}

#pragma clang diagnostic pop

@end

This will replace the default implementation and most UIControls use systemFont.

Answer 4

If you're using Swift, you can create a UILabel extension:

extension UILabel {

    @objc var substituteFontName : String {
        get { return self.font.fontName }
        set { self.font = UIFont(name: newValue, size: self.font.pointSize) }
    }

}

And then where you do your appearance proxying:

UILabel.appearance().substituteFontName = applicationFont

There is equivalent Objective-C code using UI_APPEARANCE_SELECTOR on a property with the name substituteFontName.

Addition

For the case where you'd want to set bold and regular fonts separately:

extension UILabel {

    @objc var substituteFontName : String {
        get { return self.font.fontName }
        set { 
            if self.font.fontName.range(of:"Medium") == nil { 
                self.font = UIFont(name: newValue, size: self.font.pointSize)
            }
        }
    }

    @objc var substituteFontNameBold : String {
        get { return self.font.fontName }
        set { 
            if self.font.fontName.range(of:"Medium") != nil { 
                self.font = UIFont(name: newValue, size: self.font.pointSize)
            }
        }
    }
}

Then for your UIAppearance proxies:

UILabel.appearance().substituteFontName = applicationFont
UILabel.appearance().substituteFontNameBold = applicationFontBold

Note: if you're finding that the bold substitution isn't working, it's possible the default font name doesn't contain "Medium". Switch out that string for another match as needed (thanks to Mason in the comments below) .

Answer 5

Developing from Hugues BR answer but using method swizzling I've arrived to a solution that is successfully changing all the fonts to a desired font in my app.

An approach with Dynamic Type should be what you should look for on iOS 7. The following solution is not using Dynamic Type.

---

Notes:

• the code below, in its presented state, was never submitted to Apple approval;
• there is a shorter version of it that passed Apple submission, that is without the - initWithCoder: override. However that won't cover all the cases;
• the following code is present in a class I use to set the style of my app which is included by my AppDelegate class thus being available everywhere and to all UIFont instances;
• I'm using Zapfino here just to make the changes much more visible;
• any improvement you may find to this code is welcome.

---

This solution uses two different methods to achieve the final result. The first is override the UIFont class methods + systemFontWithSize: and similar with ones that use my alternatives (here I use "Zapfino" to leave no doubts that the replacement was successful).

The other method is to override - initWithCoder: method on UIFont to replace any occurrence of CTFontRegularUsage and similar by my alternatives. This last method was necessary because I've found that UILabel objects encoded in NIB files don't check the + systemFontWithSize: methods to get their system font and instead encode them as UICTFontDescriptor objects. I've tried to override - awakeAfterUsingCoder: but somehow it was getting called for every encoded object in my storyboard and causing crashes. Overriding - awakeFromNib wouldn't allow me to read the NSCoder object.

#import <objc/runtime.h>

NSString *const FORegularFontName = @"Zapfino";
NSString *const FOBoldFontName = @"Zapfino";
NSString *const FOItalicFontName = @"Zapfino";

#pragma mark - UIFont category
@implementation UIFont (CustomFonts)

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wobjc-protocol-method-implementation"
+ (void)replaceClassSelector:(SEL)originalSelector withSelector:(SEL)modifiedSelector {
    Method originalMethod = class_getClassMethod(self, originalSelector);
    Method modifiedMethod = class_getClassMethod(self, modifiedSelector);
    method_exchangeImplementations(originalMethod, modifiedMethod);
}

+ (void)replaceInstanceSelector:(SEL)originalSelector withSelector:(SEL)modifiedSelector {
    Method originalDecoderMethod = class_getInstanceMethod(self, originalSelector);
    Method modifiedDecoderMethod = class_getInstanceMethod(self, modifiedSelector);
    method_exchangeImplementations(originalDecoderMethod, modifiedDecoderMethod);
}

+ (UIFont *)regularFontWithSize:(CGFloat)size
{
    return [UIFont fontWithName:FORegularFontName size:size];
}

+ (UIFont *)boldFontWithSize:(CGFloat)size
{
    return [UIFont fontWithName:FOBoldFontName size:size];
}

+ (UIFont *)italicFontOfSize:(CGFloat)fontSize
{
    return [UIFont fontWithName:FOItalicFontName size:fontSize];
}

- (id)initCustomWithCoder:(NSCoder *)aDecoder {
    BOOL result = [aDecoder containsValueForKey:@"UIFontDescriptor"];

    if (result) {
        UIFontDescriptor *descriptor = [aDecoder decodeObjectForKey:@"UIFontDescriptor"];

        NSString *fontName;
        if ([descriptor.fontAttributes[@"NSCTFontUIUsageAttribute"] isEqualToString:@"CTFontRegularUsage"]) {
            fontName = FORegularFontName;
        }
        else if ([descriptor.fontAttributes[@"NSCTFontUIUsageAttribute"] isEqualToString:@"CTFontEmphasizedUsage"]) {
            fontName = FOBoldFontName;
        }
        else if ([descriptor.fontAttributes[@"NSCTFontUIUsageAttribute"] isEqualToString:@"CTFontObliqueUsage"]) {
            fontName = FOItalicFontName;
        }
        else {
            fontName = descriptor.fontAttributes[@"NSFontNameAttribute"];
        }

        return [UIFont fontWithName:fontName size:descriptor.pointSize];
    }

    self = [self initCustomWithCoder:aDecoder];

    return self;
}

+ (void)load
{
    [self replaceClassSelector:@selector(systemFontOfSize:) withSelector:@selector(regularFontWithSize:)];
    [self replaceClassSelector:@selector(boldSystemFontOfSize:) withSelector:@selector(boldFontWithSize:)];
    [self replaceClassSelector:@selector(italicSystemFontOfSize:) withSelector:@selector(italicFontOfSize:)];

    [self replaceInstanceSelector:@selector(initWithCoder:) withSelector:@selector(initCustomWithCoder:)];
}
#pragma clang diagnostic pop

@end

Answer 6

To complete Sandy Chapman's answer, here is a solution in Objective-C (put this category anywhere you want to change UILabel Appearance):

@implementation UILabel (FontOverride)
- (void)setSubstituteFontName:(NSString *)name UI_APPEARANCE_SELECTOR {
    self.font = [UIFont fontWithName:name size:self.font.pointSize];
}
@end

The interface file, should have this method declared publicly to be used later from places like your app delegate:

@interface UILabel (FontOverride)
  - (void)setSubstituteFontName:(NSString *)name UI_APPEARANCE_SELECTOR;
@end

Then, you can change the Appearance with:

[[UILabel appearance] setSubstituteFontName:@"SourceSansPro-Light"];

Answer 7

I created my own conversion of typography for Swift 4 after reviewing a few posts, it covers most of the cases, such as:

1st Add fonts to project estructure and to .plist file (with the same name):

<key>UIAppFonts</key>
<array>
    <string>Typo-Light.ttf</string>
    <string>Typo-Regular.ttf</string>
    <string>Typo-Semibold.ttf</string>
    <string>Typo-LightItalic.ttf</string>
</array>

Then

struct Resources {

    struct Fonts {
        //struct is extended in Fonts
    }
}

extension Resources.Fonts {

    enum Weight: String {
        case light = "Typo-Light"
        case regular = "Typo-Regular"
        case semibold = "Typo-Semibold"
        case italic = "Typo-LightItalic"
    }
}

extension UIFontDescriptor.AttributeName {
    static let nsctFontUIUsage = UIFontDescriptor.AttributeName(rawValue: "NSCTFontUIUsageAttribute")
}

extension UIFont {

    @objc class func mySystemFont(ofSize: CGFloat, weight: UIFont.Weight) -> UIFont {
        switch weight {
        case .semibold, .bold, .heavy, .black:
            return UIFont(name: Resources.Fonts.Weight.semibold.rawValue, size: ofSize)!

        case .medium, .regular:
            return UIFont(name: Resources.Fonts.Weight.regular.rawValue, size: ofSize)!

        default:
            return UIFont(name: Resources.Fonts.Weight.light.rawValue, size: ofSize)!
        }
    }

    @objc class func mySystemFont(ofSize size: CGFloat) -> UIFont {
        return UIFont(name: Resources.Fonts.Weight.light.rawValue, size: size)!
    }

    @objc class func myBoldSystemFont(ofSize size: CGFloat) -> UIFont {
        return UIFont(name: Resources.Fonts.Weight.semibold.rawValue, size: size)!
    }

    @objc class func myItalicSystemFont(ofSize size: CGFloat) -> UIFont {
        return UIFont(name: Resources.Fonts.Weight.italic.rawValue, size: size)!
    }

    @objc convenience init(myCoder aDecoder: NSCoder) {
        guard
            let fontDescriptor = aDecoder.decodeObject(forKey: "UIFontDescriptor") as? UIFontDescriptor,
            let fontAttribute = fontDescriptor.fontAttributes[.nsctFontUIUsage] as? String else {
                self.init(myCoder: aDecoder)
                return
        }
        var fontName = ""
        switch fontAttribute {
        case "CTFontRegularUsage", "CTFontMediumUsage":
            fontName = Resources.Fonts.Weight.regular.rawValue
        case "CTFontEmphasizedUsage", "CTFontBoldUsage", "CTFontSemiboldUsage","CTFontHeavyUsage", "CTFontBlackUsage":
            fontName = Resources.Fonts.Weight.semibold.rawValue
        case "CTFontObliqueUsage":
            fontName = Resources.Fonts.Weight.italic.rawValue
        default:
            fontName = Resources.Fonts.Weight.light.rawValue
        }
        self.init(name: fontName, size: fontDescriptor.pointSize)!
    }

    class func overrideDefaultTypography() {
        guard self == UIFont.self else { return }

        if let systemFontMethodWithWeight = class_getClassMethod(self, #selector(systemFont(ofSize: weight:))),
            let mySystemFontMethodWithWeight = class_getClassMethod(self, #selector(mySystemFont(ofSize: weight:))) {
            method_exchangeImplementations(systemFontMethodWithWeight, mySystemFontMethodWithWeight)
        }

        if let systemFontMethod = class_getClassMethod(self, #selector(systemFont(ofSize:))),
            let mySystemFontMethod = class_getClassMethod(self, #selector(mySystemFont(ofSize:))) {
            method_exchangeImplementations(systemFontMethod, mySystemFontMethod)
        }

        if let boldSystemFontMethod = class_getClassMethod(self, #selector(boldSystemFont(ofSize:))),
            let myBoldSystemFontMethod = class_getClassMethod(self, #selector(myBoldSystemFont(ofSize:))) {
            method_exchangeImplementations(boldSystemFontMethod, myBoldSystemFontMethod)
        }

        if let italicSystemFontMethod = class_getClassMethod(self, #selector(italicSystemFont(ofSize:))),
            let myItalicSystemFontMethod = class_getClassMethod(self, #selector(myItalicSystemFont(ofSize:))) {
            method_exchangeImplementations(italicSystemFontMethod, myItalicSystemFontMethod)
        }

        if let initCoderMethod = class_getInstanceMethod(self, #selector(UIFontDescriptor.init(coder:))),
            let myInitCoderMethod = class_getInstanceMethod(self, #selector(UIFont.init(myCoder:))) {
            method_exchangeImplementations(initCoderMethod, myInitCoderMethod)
        }
    }
}

Finally call to created method at Appdelegate like next:

class AppDelegate: UIResponder, UIApplicationDelegate {
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey : Any]? = nil) -> Bool {

        UIFont.overrideDefaultTypography()
        return true
    }
}

Answer 8

COMMENT FOR SWIFT 3.0 AND SWIFT WARNING

You can remove the warning message in line:

let initCoderMethod = class_getInstanceMethod(self, Selector("initWithCoder:"))

By replacing it with:

let initCoderMethod = class_getInstanceMethod(self, #selector(UIFontDescriptor.init(coder:)))

Answer 9

For Swift 5

All the above answers are correct but i have done in little different way that is according to device size. Here, in ATFontManager class, i have made default font size which is define at the top of the class as defaultFontSize, this is the font size of iphone plus and you can changed according to your requirement.

class ATFontManager: UIFont{
    
    class func setFont( _ iPhone7PlusFontSize: CGFloat? = nil,andFontName fontN : String = FontName.helveticaNeue) -> UIFont{
        
        let defaultFontSize : CGFloat = 16
        
        switch ATDeviceDetector().screenType {
            
        case .iPhone4:
            if let fontSize = iPhone7PlusFontSize{
                return UIFont(name: fontN, size: fontSize - 5)!
            }
            return UIFont(name: fontN, size: defaultFontSize - 5)!
            
        case .iPhone5:
            if let fontSize = iPhone7PlusFontSize{
                return UIFont(name: fontN, size: fontSize - 3)!
            }
            return UIFont(name: fontN, size: defaultFontSize - 3)!
            
        case .iPhone6AndIphone7, .iPhoneUnknownSmallSize:
            if let fontSize = iPhone7PlusFontSize{
                return UIFont(name: fontN, size: fontSize - 2)!
            }
            return UIFont(name: fontN, size: defaultFontSize - 2)!
            
        case .iPhone6PAndIPhone7P, .iPhoneUnknownBigSize:
            
            return UIFont(name: fontN, size: iPhone7PlusFontSize ?? defaultFontSize)!
        case .iPhoneX, .iPhoneXsMax:
            
            return UIFont(name: fontN, size: iPhone7PlusFontSize ?? defaultFontSize)!
          
        case .iPadMini:
            if let fontSize = iPhone7PlusFontSize{
                return UIFont(name: fontN, size: fontSize + 2)!
            }
            return UIFont(name: fontN, size: defaultFontSize + 2)!
            
        case .iPadPro10Inch:
            if let fontSize = iPhone7PlusFontSize{
                return UIFont(name: fontN, size: fontSize + 4)!
            }
            return UIFont(name: fontN, size: defaultFontSize + 4)!
            
        case .iPadPro:
            if let fontSize = iPhone7PlusFontSize{
                return UIFont(name: fontN, size: fontSize + 6)!
            }
            return UIFont(name: fontN, size: defaultFontSize + 6)!
            
        case .iPadUnknownSmallSize:
            
            return UIFont(name: fontN, size: defaultFontSize + 2)!
            
        case .iPadUnknownBigSize:
            
            return UIFont(name: fontN, size: defaultFontSize + 4)!
            
        default:
            
            return UIFont(name: fontN, size: iPhone7PlusFontSize ?? 16)!
        }
    }
}
     

I have added certain font name, for more you can add the font name and type here.

   enum FontName : String {
        case HelveticaNeue = "HelveticaNeue"
        case HelveticaNeueUltraLight = "HelveticaNeue-UltraLight"
        case HelveticaNeueBold = "HelveticaNeue-Bold"
        case HelveticaNeueBoldItalic = "HelveticaNeue-BoldItalic"
        case HelveticaNeueMedium = "HelveticaNeue-Medium"
        case AvenirBlack = "Avenir-Black"
        case ArialBoldMT = "Arial-BoldMT"
        case HoeflerTextBlack = "HoeflerText-Black"
        case AMCAPEternal = "AMCAPEternal"
    }

This class refers to device detector in order to provide appropriate font size according to device.

class ATDeviceDetector {
    
    var iPhone: Bool {
        
        return UIDevice().userInterfaceIdiom == .phone
    }
    
    var ipad : Bool{
        
        return UIDevice().userInterfaceIdiom == .pad
    }
    
    let isRetina = UIScreen.main.scale >= 2.0
    
    
    enum ScreenType: String {
        
        case iPhone4
        case iPhone5
        case iPhone6AndIphone7
        case iPhone6PAndIPhone7P
        case iPhoneX
        
        case iPadMini
        case iPadPro
        case iPadPro10Inch
        
        case iPhoneOrIPadSmallSizeUnknown
        case iPadUnknown
        case unknown
    }
    
    
    struct ScreenSize{
        
        static let SCREEN_WIDTH         = UIScreen.main.bounds.size.width
        static let SCREEN_HEIGHT        = UIScreen.main.bounds.size.height
        static let SCREEN_MAX_LENGTH    = max(ScreenSize.SCREEN_WIDTH,ScreenSize.SCREEN_HEIGHT)
        static let SCREEN_MIN_LENGTH    = min(ScreenSize.SCREEN_WIDTH,ScreenSize.SCREEN_HEIGHT)
    }
    
    
    var screenType: ScreenType {
        
        switch ScreenSize.SCREEN_MAX_LENGTH {
            
        case 0..<568.0:
            return .iPhone4
        case 568.0:
            return .iPhone5
        case 667.0:
            return .iPhone6AndIphone7
        case 736.0:
            return .iPhone6PAndIPhone7P
        case 812.0:
            return .iPhoneX
        case 568.0..<812.0:
            return .iPhoneOrIPadSmallSizeUnknown
        case 1112.0:
            return .iPadPro10Inch
        case 1024.0:
            return .iPadMini
        case 1366.0:
            return .iPadPro
        case 812.0..<1366.0:
            return .iPadUnknown
        default:
            return .unknown
        }
    }
}

How to use. Hope it will help.

//for default 
label.font = ATFontManager.setFont()

//if you want to provide as your demand. Here **iPhone7PlusFontSize** variable is denoted as font size for *iphone 7plus and iphone 6 plus*, and it **ATFontManager** class automatically handle.
label.font = ATFontManager.setFont(iPhone7PlusFontSize: 15, andFontName: FontName.HelveticaNeue.rawValue)

Answer 10

None of these solutions works universally throughout the app. One thing I found to help manage the fonts in Xcode is opening the Storyboard as Source code (Control-click storyboard in Files navigator > "Open as" > "Source"), and then doing a find-and-replace.

Answer 11

Font type always be set in code and nib/storyboard.

For the code,just like Hugues BR said,do it in catagory can solve the problem.

For the nib/storyboard,we can Method Swizzling awakeFromNib to change font type since UI element from nib/storyboard always call it before show in the screen.

I suppose you know Aspects.It's a library for AOP programing,based on Method Swizzling. We create catagory for UILabel,UIButton,UITextView to implement it.

UILabel:

#import "UILabel+OverrideBaseFont.h"
#import "Aspects.h"

@implementation UILabel (OverrideBaseFont)

+ (void)load {
    [[self class]aspect_hookSelector:@selector(awakeFromNib) withOptions:AspectPositionAfter usingBlock:^(id<AspectInfo> aspectInfo) {
        UILabel* instance = [aspectInfo instance];
        UIFont* font = [UIFont fontWithName:@"HelveticaNeue-light" size:instance.font.pointSize];
        instance.font = font;
    }error:nil];
}

@end

UIButton:

#import "UIButton+OverrideBaseFont.h"
#import "Aspects.h"

@implementation UIButton (OverrideBaseFont)

+ (void)load {
    [[self class]aspect_hookSelector:@selector(awakeFromNib) withOptions:AspectPositionAfter usingBlock:^(id<AspectInfo> aspectInfo) {
        UIButton* instance = [aspectInfo instance];
        UILabel* label = instance.titleLabel;
        UIFont* font = [UIFont fontWithName:@"HelveticaNeue-light" size:label.font.pointSize];
        instance.titleLabel.font = font;
    }error:nil];
}

@end

UITextField:

#import "UITextField+OverrideBaseFont.h"
#import "Aspects.h"

@implementation UITextField (OverrideBaseFont)

+ (void)load {
    [[self class]aspect_hookSelector:@selector(awakeFromNib) withOptions:AspectPositionAfter usingBlock:^(id<AspectInfo> aspectInfo) {
        UITextField* instance = [aspectInfo instance];
        UIFont* font = [UIFont fontWithName:@"HelveticaNeue-light" size:instance.font.pointSize];
        instance.font = font;
    }error:nil];
}

@end

UITextView:

#import "UITextView+OverrideBaseFont.h"
#import "Aspects.h"

@implementation UITextView (OverrideBaseFont)

+ (void)load {
    [[self class]aspect_hookSelector:@selector(awakeFromNib) withOptions:AspectPositionAfter usingBlock:^(id<AspectInfo> aspectInfo) {
        UITextView* instance = [aspectInfo instance];
        UIFont* font = [UIFont fontWithName:@"HelveticaNeue-light" size:instance.font.pointSize];
        instance.font = font;
    }error:nil];
}

@end

That's all,you can change HelveticaNeue-light to a macro with your font name.

Answer 12

Probably not, you will probably have the set the font on your control yourself, but you can make the process easier by centralizing where you get the font types from, for example have the app delegate or some other common class have a method that returns the font, and anything needing to set the font can call that method, that will help in case you need to change your font, youd change it in one place rather than everywhere you set the fonts...Another alternative can be to make subclasses of your UI Elements that will automatically set the font, but that might be overkill..

Answer 13

NUI is an alternative to the UIAppearance proxy. It gives you control over the font (and many other attributes) of a large number of UI element types throughout your application by simply modifying a style sheet, which can be reused across multiple applications.

After adding a NUILabel class to your labels, you could easily control their font in the style sheet:

LabelFontName    String    Helvetica

If you have labels with different font sizes, you could control their sizes using NUI's Label, LargeLabel, and SmallLabel classes, or even quickly create your own classes.

Answer 14

Am using like this type of font class in swift. Using font extension class.

enum FontName: String {

  case regular      = "Roboto-Regular"

}

//MARK: - Set Font Size
enum FontSize: CGFloat {
    case size = 10

}
extension UIFont {

    //MARK: - Bold Font
  class var regularFont10: UIFont {
        return UIFont(name: FontName.regular.rawValue, size:FontSize.size.rawValue )!
    }
}

Answer 15

For Xamarin.iOS inside AppDelegate's FinishedLaunching() put code like this :-

UILabel.Appearance.Font= UIFont.FromName("Lato-Regular", 14);

set font for the entire application and Add 'UIAppFonts' key on Info.plist , the path should be the path where your font file .ttf is situated .For me it was inside 'fonts' folder in my project.

<key>UIAppFonts</key>
    <array>
        <string>fonts/Lato-Regular.ttf</string>
    </array>

Answer 16

As @Randall in his answer mentioned iOS 5.0+ UIAppearance proxy can be used to customize the appearance of all instances of a class read more.

UILabel.appearance().font = .systemFont(ofSize: 17, weight: .regular)

Answer 17

We have achieved the same in Swift -Xcode 7.2 using Parent View Controller and Child view controller (Inheritance).

File - New - Cocoa Touch class - ParentViewController.

    import UIKit
    import Foundation

    class ParentViewController: UIViewController {

        var appUIColor:UIColor = UIColor.redColor()
        var appFont:UIFont = UIFont(name: "Copperplate", size: 20)!

        override func viewDidLoad() {
            super.viewDidLoad()
        }
        func addStatusBar()
        {
            let view = UIView(frame:
                CGRect(x: 0.0, y: 0.0, width: UIScreen.mainScreen().bounds.size.width, height: 20.0)
            )
            view.backgroundColor = appUIColor
            self.view.addSubview(view)
        }
    }    

Make child view controllers and associate with a StoryBoard VC, add a textLabel.

    import UIKit

    class FontTestController: ParentViewController {
        @IBOutlet var testLabel: UILabel!

        override func viewDidLoad() {
            super.viewDidLoad()
            testLabel.font =  appFont
            testLabel.textColor = appUIColor
        }

OR Make a custom UILabel Class(Sub classing method) and associate required labels to it.

import Foundation
import UIKit

class CustomFontLabel: UILabel {
    required init(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)!
        backgroundColor = ParentViewController().appUIColor
        font = ParentViewController().appFont
        textColor = UIColor.blackColor()
    }
}

Note: The Font and colour declared in Parent VC are implemented in CustomFontLabel . The advantage is we can alter the properties of uilabel/any view all together in some simple changes in Parent VC.

2)'for' looping UIView for sub views. It works only on a particular VC.

    override func viewWillLayoutSubviews() {
            for view in self.view.subviews  {
                if view.isKindOfClass(UITextField) {
                UITextField.appearance().font =  UIFont(name: "Copperplate", size: 20)
                }
                if view.isKindOfClass(UILabel) {
                    UILabel.appearance().font =  UIFont(name: "Copperplate", size: 20)    
                }               
            }       
        }