详解iOS 关于字体根据不同屏幕尺寸等比适配的问题

#import <UIKit/UIKit.h>
#import <objc/runtime.h>

/**
 * 按钮
 */
@interface UIButton (myFont)

@end

/**
 * Label
 */
@interface UILabel (myFont)

@end

#import "UIButton+MyFont.h"

//不同设备的屏幕比例(当然倍数可以自己控制)
#define SizeScale ((IPHONE_HEIGHT > 568) ? IPHONE_HEIGHT/568 : 1)

@implementation UIButton (myFont)

+ (void)load{
  Method imp = class_getInstanceMethod([self class], @selector(initWithCoder:));
  Method myImp = class_getInstanceMethod([self class], @selector(myInitWithCoder:));
  method_exchangeImplementations(imp, myImp);
}

- (id)myInitWithCoder:(NSCoder*)aDecode{
  [self myInitWithCoder:aDecode];
  if (self) {
    //部分不像改变字体的 把tag值设置成333跳过
    if(self.titleLabel.tag != 333){
      CGFloat fontSize = self.titleLabel.font.pointSize;
      self.titleLabel.font = [UIFont systemFontOfSize:fontSize*SizeScale];
    }
  }
  return self;
}


@end

@implementation UILabel (myFont)

+ (void)load{
  Method imp = class_getInstanceMethod([self class], @selector(initWithCoder:));
  Method myImp = class_getInstanceMethod([self class], @selector(myInitWithCoder:));
  method_exchangeImplementations(imp, myImp);
}

- (id)myInitWithCoder:(NSCoder*)aDecode{
  [self myInitWithCoder:aDecode];
  if (self) {
    //部分不像改变字体的 把tag值设置成333跳过
    if(self.tag != 333){
      CGFloat fontSize = self.font.pointSize;
      self.font = [UIFont systemFontOfSize:fontSize*SizeScale];
    }
  }
  return self;
}

@end