iOS Different Font Sizes within Single Size Class

问题:

In iOS 8, we can design a different UI layout for each size class. The issue I'm facing is, I've designed a layout for Compact Width and Regular Height (size class for all iPhones in portrait) but i want to keep font size of labels smaller for 3.5 and 4 inch devices (iPhone 4 and 5), then relatively bigger for 4.7 inch (iPhone 6) and more bigger for 5.5 inch (iPhone 6 Plus) devices. I've searched but unable to find a solution to set different font size for different devices within same size class.

回答1:

Edit: I don't recommend this anymore. This approach doesn't scale well when new devices come out. Use a combination of dynamic font sizes and size classes-specific fonts.

---

Say a new iPhone model comes out, if you are using Auto Layout and Size Classes you don't have to fix all the constraints manually to make your app compatible with this newer device. However, you can still set the font size of the UILabel using the following code:

if UIScreen.mainScreen().bounds.size.height == 480 {
    // iPhone 4
    label.font = label.font.fontWithSize(20)     
} else if UIScreen.mainScreen().bounds.size.height == 568 {
    // IPhone 5
    label.font = label.font.fontWithSize(20)
} else if UIScreen.mainScreen().bounds.size.width == 375 {
    // iPhone 6
    label.font = label.font.fontWithSize(20)
} else if UIScreen.mainScreen().bounds.size.width == 414 {
    // iPhone 6+
    label.font = label.font.fontWithSize(20)
} else if UIScreen.mainScreen().bounds.size.width == 768 {
    // iPad
    label.font = label.font.fontWithSize(20)
}

回答2:

I'm handling it in a project in Swift 3+ using a UILabel Custom class, UILabel extension, and UIDevice extension as generic solution.

UIDevice extension to get screenType:

public extension UIDevice {

    var iPhone: Bool {
        return UIDevice().userInterfaceIdiom == .phone
    }

    enum ScreenType: String {
        case iPhone4
        case iPhone5
        case iPhone6
        case iPhone6Plus
        case iPhoneX
        case Unknown
    }

    var screenType: ScreenType {
        guard iPhone else { return .Unknown}
        switch UIScreen.main.nativeBounds.height {
        case 960:
            return .iPhone4
        case 1136:
            return .iPhone5
        case 1334:
            return .iPhone6
        case 2208:
            return .iPhone6Plus
        case 2436:
            return .iPhoneX
        default:
            return .Unknown
        }
    }

}

Following is the UILabel extension that uses screenType to adjust font size. adjustsFontSizeToFitDevice method could be added in UILabel custom class too, but I've put it in UILabel extension to make it accessible from all types of UILabel instances.

The constant "2" used in adjustsFontSizeToFitDevice method can be changed to any desired number. My logic is to consider iPhone 6/7/8 as default resolution, and give suitable font size (in Storyboard) to each label for that resolution. Then, I'm adding 2 points for iPhone X and iPhone 6/7/8 Plus, whereas subtracting 2 points for iPhone 4/5.

extension UILabel {

    func adjustsFontSizeToFitDevice() {

        switch UIDevice().screenType {
        case .iPhone4, .iPhone5:
            font = font.withSize(font.pointSize - 2)
            break
        case .iPhone6Plus, .iPhoneX:
            font = font.withSize(font.pointSize + 2)
            break
        default:
            font = font.withSize(font.pointSize)
        }
    }

}

Finally a UILabel custom class to apply font adjustment to all labels that are sub-classed from MyCustomLabel.

class MyCustomLabel: UILabel {

    // MARK: - Life Cycle Methods

    override func awakeFromNib() {
        super.awakeFromNib()

        adjustsFontSizeToFitDevice()
    }

}

Usage: In Storyboard, sub-class all those instances of UILabel from MyCustomLabel whose font size needs to be adjusted according to device size.

回答3:

You can achieve desired effect as below.

Usage : instead of using 14 as font size you can use 14.fontSize, it will changed as per device, depends on you delta value.

No need to add conditions everyWhere in code. Only one time as below.

Usage: UIFont.font_medium(12.fontSize)

UIFont extension:

extension UIFont {    
    class func font_medium(_ size : CGFloat) -> UIFont {
        return UIFont(name: "EncodeSans-Medium", size: size)!;
    }    
}

UIDevice Extension:

extension UIDevice {
    enum DeviceTypes {
        case iPhone4_4s
        case iPhone5_5s
        case iPhone6_6s
        case iPhone6p_6ps
        case after_iPhone6p_6ps
    }

    static var deviceType : DeviceTypes {
        switch UIScreen.main.height {
        case 480.0:
            return .iPhone4_4s
        case 568.0:
            return .iPhone5_5s
        case 667.0:
            return .iPhone6_6s
        case 736.0:
            return .iPhone6p_6ps
        default:
            return .after_iPhone6p_6ps
        }
    }
}

Int Extension:

extension Int{

    var fontSize : CGFloat {

        var deltaSize : CGFloat = 0;
        switch (UIDevice.deviceType) {
        case .iPhone4_4s,
             .iPhone5_5s :
            deltaSize = -1;
        case .iPhone6_6s :
            deltaSize = 2;
        case .iPhone6p_6ps :
            deltaSize = 2;
        default:
            deltaSize = 0;
        }

        let selfValue = self;
        return CGFloat(selfValue) + deltaSize;
    }
}

回答4:

Two ways:

1)Manually make a method in app delegate, share its object and call method.

eg :

    var device = UIDevice.currentDevice().model

    if (device == "iPhone" || device == "iPhone Simulator" || device == "iPod touch")
        {
            labelboarder.frame = CGRectMake(0,self.usernameTF.frame.height-10, self.usernameTF.frame.width, 1)
            labelboarder1.frame = CGRectMake(0,self.usernameTF.frame.height-10, self.usernameTF.frame.width,1)
        }
    else
        {
            labelboarder.frame = CGRectMake(0,self.usernameTF.frame.height, 500, 1)
            labelboarder1.frame = CGRectMake(0,self.usernameTF.frame.height, 500,1)
        }

2) On every UI item, go to attributes inspector, declare a font.

(There is a + sign visible to the left of Font size field. Click on it ,select the matching size class and declare font size.)

The second option is convenient for me. Happy Coding!

回答5:

Instead of writing code for each and every label, do just extend your label class with Your custom label class as below and it will automatically scale based on device resolution scaling factor:

#define  SCALE_FACTOR_H ( [UIScreen mainScreen].bounds.size.height / 568 )


CustomLabel.h

#import <UIKit/UIKit.h>

@interface CustomLabel : UILabel

@end


CustomLabel.m
#import "CustomLabel.h"

@implementation CustomLabel

/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
    // Drawing code
}
*/
- (id)initWithCoder:(NSCoder *)aDecoder {
    if( (self = [super initWithCoder:aDecoder]) ){
        [self layoutIfNeeded];
        [self configurefont];
    }
    return self;
}

- (void) configurefont {
    CGFloat newFontSize = (self.font.pointSize * SCALE_FACTOR_H);
    self.font = [UIFont fontWithName:self.font.fontName size:newFontSize];
}
@end

回答6:

Thats the way how I did it. It's written in Swift 4 :)

enum DeviceSize {
    case big, medium, small
}

protocol Fontadjustable {

    var devicetype: DeviceSize { get }

    func adjustFontSizeForDevice()
}

extension UILabel: Fontadjustable {

    var devicetype: DeviceSize {
        switch UIScreen.main.nativeBounds.height {
        case 1136:
            return .small
        case 1334:
            return .medium
        case 2208:
            return .big
        case 2436:
            return .big
        default:
            return .big
        }
    }

    func adjustFontSizeForDevice() {
        switch self.devicetype {
        case .small:
            self.font = font.withSize(font.pointSize)
        case .medium:
            self.font = font.withSize(font.pointSize + 5)
        case .big:
            self.font = font.withSize(font.pointSize + 10)
        }
    }
}

USAGE : myawesomeLabel.adjustFontSizeForDevice()

回答7:

Create like this,

#define VIEWHEIGHT       ([[UIScreen mainScreen] bounds].size.height)
#define VIEWWIDTH        ([[UIScreen mainScreen] bounds].size.width)
#define FONTNAME_LIGHT   @"AppleSDGothicNeo-Regular"
#define FONTNAME_BOLD    @"AppleSDGothicNeo-Bold"
#define LFONT_16         [UIFont fontWithName:FONTNAME_LIGHT size:16]

after that where you want to change label font we can write simple Switch case

switch ((VIEWHEIGHT == 568)?1:((VIEWHEIGHT == 667)?2:3)) {
    case 1:{
        boldFont = BFONT_16;
    }
        break;
    case 2:{
        privacyFont = LFONT_18;
        boldFont = BFONT_18;
    }
        break;
    default:{
        privacyFont = LFONT_20;
        boldFont = BFONT_20;
    }
        break;
}

Swift Version

func isPhoneDevice() -> Bool {
    return UIDevice.current.userInterfaceIdiom == .phone
}

func isDeviceiPad() -> Bool {
    return UIDevice.current.userInterfaceIdiom == .pad
}

func isPadProDevice() -> Bool {
    let SCREEN_WIDTH = Float(UIScreen.main.bounds.size.width)
    let SCREEN_HEIGHT = Float(UIScreen.main.bounds.size.height)
    let SCREEN_MAX_LENGTH: Float = fmax(SCREEN_WIDTH, SCREEN_HEIGHT)

    return UIDevice.current.userInterfaceIdiom == .pad && SCREEN_MAX_LENGTH == 1366.0
}

func isPhoneXandXSDevice() -> Bool {
    let SCREEN_WIDTH = CGFloat(UIScreen.main.bounds.size.width)
    let SCREEN_HEIGHT = CGFloat(UIScreen.main.bounds.size.height)
    let SCREEN_MAX_LENGTH: CGFloat = fmax(SCREEN_WIDTH, SCREEN_HEIGHT)

    return UIDevice.current.userInterfaceIdiom == .phone && SCREEN_MAX_LENGTH == 812.0
}

func isPhoneXSMaxandXRDevice() -> Bool {
    let SCREEN_WIDTH = CGFloat(UIScreen.main.bounds.size.width)
    let SCREEN_HEIGHT = CGFloat(UIScreen.main.bounds.size.height)
    let SCREEN_MAX_LENGTH: CGFloat = fmax(SCREEN_WIDTH, SCREEN_HEIGHT)

    return UIDevice.current.userInterfaceIdiom == .phone && SCREEN_MAX_LENGTH == 896.0
}