iOS13适配深色模式(Dark Mode)

原文博客地址: iOS13适配深色模式(Dark Mode)
好像大概也许是一年前, Mac OS系统发布了深色模式外观, 看着挺刺激, 时至今日用着也还挺爽的
终于, 随着iPhone11等新手机的发售, iOS 13系统也正式发布了, 伴随着手机版的深色模式也出现在了大众视野
我们这些iOS程序猿也有事情做了, 原有项目适配iOS13系统, 适配Dark Mode深色模式
虽然现在并没有要求强制适配Dark Mode, 但是DarK适配却也迫在眉睫
本人在github上查找到的一个较好的解决方案例子：https://github.com/internetWei/llDark

Apps on iOS 13 are expected to support dark mode Use system colors and materials Create your own dynamic colors and images Leverage flexible infrastructure

获取当前模式

提供两种方式设置手机当前外观模式

设置 --> 显示与亮度
控制中心, 长按亮度调节按钮

获取当前模式

我们需要选获取到当前出于什么模式, 在根据不同的模式进行适配, iOS 13中新增了获取当前模式的API

Swift

// 获取当前模式
let currentMode = UITraitCollection.current.userInterfaceStyle
if (currentMode == .dark) {
    print("深色模式")
} else if (currentMode == .light) {
    print("浅色模式")
} else {
    print("未知模式")
}

open var userInterfaceStyle: UIUserInterfaceStyle { get } 

// 所有模式
public enum UIUserInterfaceStyle : Int {
    // 未指明的
    case unspecified
    // 浅色模式
    case light
    // 深色模式
    case dark
}

OC语言

if (@available(iOS 13.0, *)) {
    UIUserInterfaceStyle mode = UITraitCollection.currentTraitCollection.userInterfaceStyle;
    if (mode == UIUserInterfaceStyleDark) {
        NSLog(@"深色模式");
    } else if (mode == UIUserInterfaceStyleLight) {
        NSLog(@"浅色模式");
    } else {
        NSLog(@"未知模式");
    }
}

// 各种枚举值
typedef NS_ENUM(NSInteger, UIUserInterfaceStyle) {
    UIUserInterfaceStyleUnspecified,
    UIUserInterfaceStyleLight,
    UIUserInterfaceStyleDark,
} API_AVAILABLE(tvos(10.0)) API_AVAILABLE(ios(12.0)) API_UNAVAILABLE(watchos);

监听系统模式的变化

在iOS13系统中, UIViewController遵循了两个协议: UITraitEnvironment和UIContentContainer协议

在UITraitEnvironment协议中, 为我们提供了一个监听当前模式变化的方法

@protocol UITraitEnvironment <NSObject>
// 当前模式
@property (nonatomic, readonly) UITraitCollection *traitCollection API_AVAILABLE(ios(8.0));

// 重写该方法监听模式的改变
- (void)traitCollectionDidChange:(nullable UITraitCollection *)previousTraitCollection API_AVAILABLE(ios(8.0));
@end

public protocol UITraitEnvironment : NSObjectProtocol {
    // 当前模式
    @available(iOS 8.0, *)
    var traitCollection: UITraitCollection { get }

    // 重写该方法监听模式的改变
    @available(iOS 8.0, *)
    func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?)
}


// 使用方法
override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
    super.traitCollectionDidChange(previousTraitCollection)
    
    // 每次模式改变的时候, 这里都会执行
    print("模式改变了")
}

颜色相关适配

不同模式的适配主要涉及颜色和图片两个方面的适配
其中颜色适配, 包括相关背景色和字体颜色
当系统模式切换的时候, 我们不需要如何操作, 系统会自动渲染页面, 只需要做好不同模式的颜色和图片即可

UIColor

iOS13之前UIColor只能表示一种颜色，从iOS13开始UIColor是一个动态的颜色，在不同模式下可以分别代表不同的颜色
下面是iOS13系统提供的动态颜色种类, 使用以下颜色值, 在模式切换时, 则不需要做特殊处理

@interface UIColor (UIColorSystemColors)
#pragma mark System colors

@property (class, nonatomic, readonly) UIColor *systemRedColor          API_AVAILABLE(ios(7.0), tvos(9.0)) API_UNAVAILABLE(watchos);
@property (class, nonatomic, readonly) UIColor *systemGreenColor        API_AVAILABLE(ios(7.0), tvos(9.0)) API_UNAVAILABLE(watchos);
@property (class, nonatomic, readonly) UIColor *systemBlueColor         API_AVAILABLE(ios(7.0), tvos(9.0)) API_UNAVAILABLE(watchos);
@property (class, nonatomic, readonly) UIColor *systemOrangeColor       API_AVAILABLE(ios(7.0), tvos(9.0)) API_UNAVAILABLE(watchos);
@property (class, nonatomic, readonly) UIColor *systemYellowColor       API_AVAILABLE(ios(7.0), tvos(9.0)) API_UNAVAILABLE(watchos);
@property (class, nonatomic, readonly) UIColor *systemPinkColor         API_AVAILABLE(ios(7.0), tvos(9.0)) API_UNAVAILABLE(watchos);
@property (class, nonatomic, readonly) UIColor *systemPurpleColor       API_AVAILABLE(ios(9.0), tvos(9.0)) API_UNAVAILABLE(watchos);
@property (class, nonatomic, readonly) UIColor *systemTealColor         API_AVAILABLE(ios(7.0), tvos(9.0)) API_UNAVAILABLE(watchos);
@property (class, nonatomic, readonly) UIColor *systemIndigoColor       API_AVAILABLE(ios(13.0), tvos(13.0)) API_UNAVAILABLE(watchos);
// 灰色种类, 在Light模式下, systemGray6Color更趋向于白色
@property (class, nonatomic, readonly) UIColor *systemGrayColor         API_AVAILABLE(ios(7.0), tvos(9.0)) API_UNAVAILABLE(watchos);
@property (class, nonatomic, readonly) UIColor *systemGray2Color        API_AVAILABLE(ios(13.0)) API_UNAVAILABLE(tvos, watchos);
@property (class, nonatomic, readonly) UIColor *systemGray3Color        API_AVAILABLE(ios(13.0)) API_UNAVAILABLE(tvos, watchos);
@property (class, nonatomic, readonly) UIColor *systemGray4Color        API_AVAILABLE(ios(13.0)) API_UNAVAILABLE(tvos, watchos);
@property (class, nonatomic, readonly) UIColor *systemGray5Color        API_AVAILABLE(ios(13.0)) API_UNAVAILABLE(tvos, watchos);
@property (class, nonatomic, readonly) UIColor *systemGray6Color        API_AVAILABLE(ios(13.0)) API_UNAVAILABLE(tvos, watchos);

#pragma mark Foreground colors
@property (class, nonatomic, readonly) UIColor *labelColor              API_AVAILABLE(ios(13.0), tvos(13.0)) API_UNAVAILABLE(watchos);
@property (class, nonatomic, readonly) UIColor *secondaryLabelColor     API_AVAILABLE(ios(13.0), tvos(13.0)) API_UNAVAILABLE(watchos);
@property (class, nonatomic, readonly) UIColor *tertiaryLabelColor      API_AVAILABLE(ios(13.0), tvos(13.0)) API_UNAVAILABLE(watchos);
@property (class, nonatomic, readonly) UIColor *quaternaryLabelColor    API_AVAILABLE(ios(13.0), tvos(13.0)) API_UNAVAILABLE(watchos);
// 系统链接的前景色
@property (class, nonatomic, readonly) UIColor *linkColor               API_AVAILABLE(ios(13.0), tvos(13.0)) API_UNAVAILABLE(watchos);
// 占位文字的颜色
@property (class, nonatomic, readonly) UIColor *placeholderTextColor    API_AVAILABLE(ios(13.0), tvos(13.0)) API_UNAVAILABLE(watchos);
// 边框或者分割线的颜色
@property (class, nonatomic, readonly) UIColor *separatorColor          API_AVAILABLE(ios(13.0), tvos(13.0)) API_UNAVAILABLE(watchos);
@property (class, nonatomic, readonly) UIColor *opaqueSeparatorColor    API_AVAILABLE(ios(13.0), tvos(13.0)) API_UNAVAILABLE(watchos);

#pragma mark Background colors
@property (class, nonatomic, readonly) UIColor *systemBackgroundColor                   API_AVAILABLE(ios(13.0)) API_UNAVAILABLE(tvos, watchos);
@property (class, nonatomic, readonly) UIColor *secondarySystemBackgroundColor          API_AVAILABLE(ios(13.0)) API_UNAVAILABLE(tvos, watchos);
@property (class, nonatomic, readonly) UIColor *tertiarySystemBackgroundColor           API_AVAILABLE(ios(13.0)) API_UNAVAILABLE(tvos, watchos);
@property (class, nonatomic, readonly) UIColor *systemGroupedBackgroundColor            API_AVAILABLE(ios(13.0)) API_UNAVAILABLE(tvos, watchos);
@property (class, nonatomic, readonly) UIColor *secondarySystemGroupedBackgroundColor   API_AVAILABLE(ios(13.0)) API_UNAVAILABLE(tvos, watchos);
@property (class, nonatomic, readonly) UIColor *tertiarySystemGroupedBackgroundColor    API_AVAILABLE(ios(13.0)) API_UNAVAILABLE(tvos, watchos);

#pragma mark Fill colors
@property (class, nonatomic, readonly) UIColor *systemFillColor                         API_AVAILABLE(ios(13.0)) API_UNAVAILABLE(tvos, watchos);
@property (class, nonatomic, readonly) UIColor *secondarySystemFillColor                API_AVAILABLE(ios(13.0)) API_UNAVAILABLE(tvos, watchos);
@property (class, nonatomic, readonly) UIColor *tertiarySystemFillColor                 API_AVAILABLE(ios(13.0)) API_UNAVAILABLE(tvos, watchos);
@property (class, nonatomic, readonly) UIColor *quaternarySystemFillColor               API_AVAILABLE(ios(13.0)) API_UNAVAILABLE(tvos, watchos);

#pragma mark Other colors
// 这两个是非动态颜色值
@property(class, nonatomic, readonly) UIColor *lightTextColor API_UNAVAILABLE(tvos);    // for a dark background
@property(class, nonatomic, readonly) UIColor *darkTextColor API_UNAVAILABLE(tvos);     // for a light background

@property(