meng
1、上篇文章说到，给UIFont添加分类，实现全局改变字号，下面就来介绍给UILabel和UIButton添加分类，在init时候改变字号
The first step：创建UILabel和UIButton的分类，如图
UILabel的分类
UILabel+changeTextFont.h
#import <UIKit/UIKit.h>
@interface UILabel (changeTextFont)
@end
UILabel+changeTextFont.m
#import "UILabel+changeTextFont.h"
@implementation UILabel (changeTextFont)
// 监听字号的改变
- (instancetype)initWithFrame:(CGRect)frame{
if (self= [super initWithFrame:frame]) {
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(changeTextSize:) name:@"changeTextSize" object:nil];
}
return self;
}
- (void)changeTextSize:(NSNotification *)noti {
//11是文字的最小字号，可以根据需求修改此字号
self.font = [UIFont systemFontOfSize:(11 * [[[NSUserDefaults standardUserDefaults] valueForKey:@"fontsize"] floatValue])];
}
@end
1.2 Button分类
button的分类
UIButton+ChangeTextFont.h
#import "UIButton+ChangeTextFont.h"
@implementation UIButton (ChangeTextFont)
// 监听字号改变
- (instancetype)initWithFrame:(CGRect)frame{
if (self = [super initWithFrame:frame]) {
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(changeTextSize:) name:@"changeTextSize" object:nil];
}
return self;
}
// 收到通知后改变字号
- (void)changeTextSize:(NSNotification *)noti{
//11是文字的最小字号，可以根据需求修改此字号
self.titleLabel.font = [UIFont systemFontOfSize:[[NSUserDefaults standardUserDefaults] floatForKey:@"fontsize"]*11];
}
@end
2 、ViewController.h
#import <UIKit/UIKit.h>
@interface ViewController : UIViewController
@end
ViewController.m
#import "ViewController.h"
#import "NextViewController.h"
// 定义文字大小的宏
#define FONT_SIZE [[[NSUserDefaults standardUserDefaults] objectForKey:@"fontsize"] floatValue] > 1 ? [[[NSUserDefaults standardUserDefaults] valueForKey:@"fontsize"] floatValue] * 11 : 11
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
self.title = @"全局改变字号";
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(50, 100, 300, 100)];
label.backgroundColor = [UIColor redColor];
label.text = @"这是测试文字";
label.font = [UIFont systemFontOfSize:FONT_SIZE];
[self.view addSubview:label];
UIButton *btn = [UIButton buttonWithType:UIButtonTypeSystem];
[btn setBackgroundColor:[UIColor yellowColor]];
btn.frame = CGRectMake(100, 200, 300, 100);
[btn setTitle:@"这是一个按钮" forState:UIControlStateNormal];
[btn setTintColor:[UIColor blackColor]];
btn.titleLabel.font = [UIFont systemFontOfSize:FONT_SIZE];
[self.view addSubview:btn];
}
// 点击屏幕任意位置，跳到设置界面
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
[self.navigationController pushViewController:[[NextViewController alloc] init] animated:YES];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
ViewController界面的效果图如下
ViewController界面效果
3、设置界面
NextViewController.h
#import <UIKit/UIKit.h>
@interface NextViewController : UIViewController
@end
NextViewController.m
#import "NextViewController.h"
@interface NextViewController ()
@end
@implementation NextViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
// 创建滑动开关
UISlider *slide = [[UISlider alloc] initWithFrame:CGRectMake(40, 200, 200, 20)];
slide.value = [[[NSUserDefaults standardUserDefaults] valueForKey:@"fontsize"] floatValue] - 1;
slide.maximumValue = 1.0;
slide.minimumValue = 0.0;
[slide addTarget:self action:@selector(change:) forControlEvents:UIControlEventValueChanged];
[self.view addSubview:slide];
}
- (void)change:(UISlider *)slide {
// 将slider的值存到本地
[[NSUserDefaults standardUserDefaults] setValue:@(slide.value + 1) forKey:@"fontsize"];
// 发送通知
[[NSNotificationCenter defaultCenter] postNotificationName:@"changeTextSize" object:nil userInfo:@{@"size":@(slide.value + 1)}];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
设置界面的效果如下
设置界面效果
此时，调节滚动条就可以实现全局改变字号了，但是会有一个问题，因为导航栏的title也是继承与UILabel，所以此时对UILabel添加分类，势必会造成调节字号的时候，导航条的字号也随之改变，有些app可能不需要改变导航条的字号，那么下面就来解决这一问题
4、如果想在调节字号的时候导航条title的字号没有改变的话，那么此时就不能对UILabel添加分类，我们可以创建一个类，继承与UILabel，用这个类来创建label，具体代码如下
首先先来创建一个类 CustomLabel
CustomLabel.h
#import <UIKit/UIKit.h>
@interface CustomLabel : UILabel
@end
CustomLabel.m
#import "CustomLabel.h"
@implementation CustomLabel
- (instancetype)initWithFrame:(CGRect)frame{
if (self= [super initWithFrame:frame]) {
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(changeTextSize:) name:@"changeTextSize" object:nil];
}
return self;
}
- (void)changeTextSize:(NSNotification *)noti {
//11是我默认设置的文字大小,你根据需求该这个数就行
self.font = [UIFont systemFontOfSize:(11 * [[[NSUserDefaults standardUserDefaults] valueForKey:@"fontsize"] floatValue])];
}
@end
创建label的时候，用这个类创建，就可以避免在调节字号的时候同时改变导航条的字号了，关于另外一种做法，在上篇文章中已经介绍过
iOS 全局改变字号（一）http://www.jianshu.com/p/824d3feeee02
