+ (NSDictionary<id, id> *)llDarkTheme {
    return @{
             UIColor.whiteColor : kColorRGB(27, 27, 27),
             kColorRGB(240, 238, 245) : kColorRGB(39, 39, 39),
             [UIColor colorWithRed:14.0 / 255.0 green:255.0 / 255.0 blue:0.0 alpha:1.0] : [UIColor colorWithRed:0.0 green:14.0 / 255.0 blue:255.0 / 255.0 alpha:1.0],
             @"background_light" : @"background_dark",
             @"~/path/background_light.png" : @"~/path/background_dark.png",
    };
}

// UIColor
UIColor.redColor; // Previous usage
UIColor.redColor.themeColor(nil); // Current usage

// CGColor
UIColor.redColor.CGColor; // Previous usage
UIColor.redColor.themeCGColor(nil); // Current usage

// UIImage
[UIImage imageNamed:@"lightImageName"]; // Previous usage
[UIImage themeImage:@"lightImageName"]; // Current usage

1.If the parameter in themeColor() is a specific Color object, the dark theme will refresh with the specified Color object.
If it is nil, it will return to the dark color refresh configured in llDarkTheme,
If llDarkTheme is not configured, it will return the color under the light theme.

2.The function of the themeCGColor() parameter is the same as the function of the themeColor() parameter.

3.themeImage() has 2 parameters, the parameter can be the image name or the image address,
The first parameter represents the picture used under the light theme (required),
The second parameter represents the picture used under the dark theme (can be empty),
If the second parameter is empty, the treatment is the same as if themeColor() is empty.

4.appearanceBindUpdater，All objects inherited from UIView have this property,
It will be called when the object needs to be refreshed, and you can implement your own refresh logic here.
It is only called when a refresh is needed, and the theme change does not necessarily require refreshing the UI.

5.userInterfaceStyle，Similar to the overrideUserInterfaceStyle method of iOS13 system,
But the function is more powerful than overrideUserInterfaceStyle,
It supports all objects, such as CALayer.
It supports system usage below iOS13.

6.themeDidChange，All objects have this property, which is the same as ThemeDidChangeNotification.
themeDidChange will be released when the object is released,
Can be used in multiple places, the callback order is not guaranteed,
Unlike appearanceBindUpdater, themeDidChange is called whenever the theme changes.

7.systemThemeDidChange，All objects have this property, which is the same as SystemThemeDidChangeNotification.
The release timing is the same as themeDidChange,
Can be used in multiple places, the callback order is not guaranteed,
As long as the system theme changes, systemThemeDidChange will be called.

8.darkStyle，All UIImageView objects have this method to adapt to image objects without dark images, such as web images.
DarkStyle has 3 parameters. The first parameter determines how to adapt to the dark theme. There are currently two types: LLDarkStyleSaturation and LLDarkStyleMask.
LLDarkStyleMask uses mask adaptation, and LLDarkStyleSaturation adapts by reducing the saturation of the original image.
The second parameter determines the transparency/saturation value of the mask. For specific usage, please refer to the source code comments.
The third parameter can be nil. When using LLDarkStyleSaturation, you need to pass a unique string as an identifier, usually the url of the image.
Sample code:
UIImageView *imageView = [[UIImageView alloc] init];
NSString *url = @"Picture URL";
imageView.darkStyle(LLDarkStyleSaturation, 0.2, url);
// imageView.darkStyle(LLDarkStyleMask, 0.5, nil);

9.updateDarkTheme:，If you need to modify the dark theme configuration information at runtime, or need to obtain dark theme configuration information from the Internet, you can use updateDarkTheme: to achieve the goal.
Please ensure that the dark theme information is configured before the first UI object is loaded, otherwise it will be invalid.
Sample code:
NSDictionary *darkTheme = @{
    UIColor.whiteColor : kColorRGB(27, 27, 27),
    kColorRGB(240, 238, 245) : kColorRGB(39, 39, 39),
    [UIColor colorWithRed:14.0 / 255.0 green:255.0 / 255.0 blue:0.0 alpha:1.0] : [UIColor colorWithRed:0.0 green:14.0 / 255.0 blue:255.0 /  255.0 alpha:1.0],
    @"background_light" : @"background_dark",
    @"~/path/background_light.png" : @"~/path/background_dark.png",
};
[LLDarkSource updateDarkTheme:darkTheme];

10.thirdControlClassName，If you need to support the refresh method of the third-party control, you can implement the refresh logic separately in appearanceBindUpdater, or you can implement the refresh logic according to the following methods, and the following methods are more recommended.
First, you need to implement the thirdControlClassName class method and return an array containing the class name string of the third party control.
Then implement the refresh+class name string object method, and implement the refresh logic of the third-party control in the method. You can refer to the YYLabel refresh logic that has been implemented in the LLThird.m file.
For details, you can download the project and view the Demo to understand the specific implementation.

+ (NSDictionary<id, id> *)llDarkTheme {
    return @{
             UIColor.whiteColor : kColorRGB(27, 27, 27),
             kColorRGB(240, 238, 245) : kColorRGB(39, 39, 39),
             [UIColor colorWithRed:14.0 / 255.0 green:255.0 / 255.0 blue:0.0 alpha:1.0] : [UIColor colorWithRed:0.0 green:14.0 / 255.0 blue:255.0 / 255.0 alpha:1.0],
             @"background_light" : @"background_dark",
             @"~/path/background_light.png" : @"~/path/background_dark.png",
    };
}

// UIColor
UIColor.redColor; // 之前的用法
UIColor.redColor.themeColor(nil); // 现在的用法

// CGColor
UIColor.redColor.CGColor; // 之前的用法
UIColor.redColor.themeCGColor(nil); // 现在的用法

// UIImage
[UIImage imageNamed:@"lightImageName"]; // 之前的用法
[UIImage themeImage:@"lightImageName"]; // 现在的用法

1.themeColor()里面的参数如果是具体的Color对象，深色主题则会使用指定的Color对象刷新,
如果是nil则会返回llDarkTheme中配置的深色颜色刷新，
如果llDarkTheme未配置则会返回浅色主题下的颜色。

2.themeCGColor()参数的作用和themeColor()参数作用一样。

3.themeImage()有2个参数，参数可以是图片名称，也可以是图片地址,
第1个参数表示浅色主题下使用的图片(必填)，
第2个参数表示深色主题下使用的图片(可以为空)，
第2个参数为空的话和themeColor()为空的处理方式一样。

4.appearanceBindUpdater，所有继承自UIView的对象都拥有这个属性，
对象需要刷新时会调用它，可以在这里实现自己的刷新逻辑。
仅在需要刷新时会调用，主题更改不一定需要刷新UI。

5.userInterfaceStyle，类似iOS13系统的overrideUserInterfaceStyle方法，
但是功能比overrideUserInterfaceStyle更加强大，
它支持所有的对象，例如CALayer。
它支持iOS13以下的系统使用。

6.themeDidChange，所有对象都拥有这个属性，作用和ThemeDidChangeNotification一样，
themeDidChange会在对象释放时被释放掉，
可以在多个地方使用，不保证回调顺序，
不同于appearanceBindUpdater，只要主题发生改变就会调用themeDidChange。

7.systemThemeDidChange，所有对象都拥有这个属性，作用和SystemThemeDidChangeNotification一样，
释放时机和themeDidChange一样，
可以在多个地方使用，不保证回调顺序，
只要系统主题发生改变就会调用systemThemeDidChange。

8.darkStyle，所有UIImageView对象都拥有这个方法，用于适配没有深色图片的图片对象，例如网络图片。
darkStyle有3个参数，第1个参数决定如何适配深色主题，目前有LLDarkStyleSaturation和LLDarkStyleMask两种，
LLDarkStyleMask使用蒙层适配，LLDarkStyleSaturation通过降低原图饱合度适配。
第2个参数决定蒙层透明度/饱合度值，具体使用可看源码注释。
第3个参数可以为nil，使用LLDarkStyleSaturation时需要传递一个唯一字符串当做标识符，通常是图片的url。
样例代码：
UIImageView *imageView = [[UIImageView alloc] init];
NSString *url = @"图片URL";
imageView.darkStyle(LLDarkStyleSaturation, 0.2, url);
// imageView.darkStyle(LLDarkStyleMask, 0.5, nil);

9.updateDarkTheme:，如果需要运行时修改深色主题配置信息，或者需要从网络上获取深色主题配置信息，可以使用updateDarkTheme:来达到目的。
请确保在第1个UI对象加载前配置好深色主题信息，否则会无效。
样例代码:
NSDictionary *darkTheme = @{
    UIColor.whiteColor : kColorRGB(27, 27, 27),
    kColorRGB(240, 238, 245) : kColorRGB(39, 39, 39),
    [UIColor colorWithRed:14.0 / 255.0 green:255.0 / 255.0 blue:0.0 alpha:1.0] : [UIColor colorWithRed:0.0 green:14.0 / 255.0 blue:255.0 /  255.0 alpha:1.0],
    @"background_light" : @"background_dark",
    @"~/path/background_light.png" : @"~/path/background_dark.png",
};
[LLDarkSource updateDarkTheme:darkTheme];

10.thirdControlClassName，如果需要支持第3方控件的刷新方法，可以在appearanceBindUpdater中单独实现刷新逻辑，也可以按照如下方法实现刷新逻辑，更加推荐如下方法。
首先需要实现thirdControlClassName这个类方法，并返回一个数组，数组包含第3方控件的类名字符串。
然后实现refresh+类名字符串的对象方法，在方法里实现第3方控件的刷新逻辑，可以参考LLThird.m文件中已经实现的YYLabel的刷新逻辑。
详情可以下载工程查看Demo了解具体实现。