//宏定義#define SCREEN_WIDTH ([UIScreen mainScreen].bounds.size.width)#define FONT_SIZE(size) ([UIFont systemFontOfSize:FontSize(size))/** * 字體適配 我在PCH文件定義了一個(gè)方法 */static inline CGFloat FontSize(CGFloat fontSize){ if (SCREEN_WIDTH==320) {  return fontSize-2; }else if (SCREEN_WIDTH==375){  return fontSize; }else{  return fontSize+2; }}

#define IsIphone6P   SCREEN_WIDTH==414#define SizeScale   (IsIphone6P ? 1.5 : 1)#define kFontSize(value) value*SizeScale#define kFont(value)  [UIFont systemFontOfSize:value*SizeScale]

#define MyUIScreen 375 // UI設(shè)計(jì)原型圖的手機(jī)尺寸寬度(6), 6p的--414

UIFont+runtime.m#import "UIFont+runtime.h"#import <objc/runtime.h>@implementation UIFont (runtime)+ (void)load { // 獲取替換后的類方法 Method newMethod = class_getClassMethod([self class], @selector(adjustFont:)); // 獲取替換前的類方法 Method method = class_getClassMethod([self class], @selector(systemFontOfSize:)); // 然后交換類方法，交換兩個(gè)方法的IMP指針，(IMP代表了方法的具體的實(shí)現(xiàn)） method_exchangeImplementations(newMethod, method);}+ (UIFont *)adjustFont:(CGFloat)fontSize { UIFont *newFont = nil; newFont = [UIFont adjustFont:fontSize * [UIScreen mainScreen].bounds.size.width/MyUIScreen]; return newFont;}@end

Controller類中正常調(diào)用就行了：UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(0, 150, [UIScreen mainScreen].bounds.size.width, 60)];label.text = @"iOS字體大小適配";label.font = [UIFont systemFontOfSize:16];[self.view addSubview:label];