创建一个 UIFont 的分类

#import <objc/runtime.h>

#define UISize_With 375  //设计参考的屏幕宽度

@implementation UIFont (JDRuntimeFont)

+(void)load{
    //获取替换后的类方法
    Method newMethod =class_getClassMethod([self class], @selector(adjustFont:));
    //获取需要替换的类方法
    Method method = class_getClassMethod([self class],@selector(systemFontOfSize:));
    //交换方法
    method_exchangeImplementations(newMethod, method);

}


+(UIFont *)adjustFont:(CGFloat)fontSize{
    UIFont *newFont=nil;
    newFont = [UIFont adjustFont:fontSize * [UIScreen mainScreen].bounds.size.width/375];
    return newFont;
}

@end

搞定!

Demo地址:https://github.com/yuying2012/WJDStudyLibrary