1.先建立一个UILabel的分类
导入#import <objc/runtime.h>头文件
2.在.m文件中写入如下代码
//不同设备的屏幕比例(当然倍数可以自己控制)
#define IPHONE_HEIGHT [UIScreen mainScreen].bounds.size.height
#define SizeScale ((IPHONE_HEIGHT > 568) ? IPHONE_HEIGHT/568 : 1)
@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);
Method cmp = class_getInstanceMethod([self class], @selector(initWithFrame:));
Method myCmp = class_getInstanceMethod([self class], @selector(myInitWithFrame:));
method_exchangeImplementations(cmp, myCmp);
}
- (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];
NSLog(@" label的大小 == %f", self.font.pointSize);
}
}
return self;
}
- (id)myInitWithFrame:(CGRect)frame{
[self myInitWithFrame:frame];
if(self){
CGFloat fontSize = self.font.pointSize;
self.font = [UIFont systemFontOfSize:fontSize * SizeScale];
NSLog(@" label的大小 == %f", self.font.pointSize);
}
return self;
}
@end
3.在调用文件中导入分类
#import "ViewController.h"
#import "UIButton+myFont.h"
@interface ViewController ()
/*注释*/
@property (nonatomic,strong)UILabel *label;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
[self.view addSubview:self.label];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)viewWillAppear:(BOOL)animated
{
NSLog(@"%@",self.label.font);
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (UILabel *)label{
if (!_label) {
_label = [[UILabel alloc]initWithFrame:CGRectMake(50, 100, 100, 30)];
// _label.font = [UIFont systemFontOfSize:17];
_label.tag = 32;
_label.text = @"这是测试文字";
}
return _label;
}
@end