UIButton(干货)--教你如何利用runtime自定义UIButton的titleLabel以及image的frame

本文来自简书，原文地址:http://www.jianshu.com/p/e5fdc00b8e31

最近做项目,会用到许多的类似美团首页button的效果,之前做法都是自定义view,view上添加button以及label来做出相同的效果,但是今天我教你极为简便的方法,只需要自定义button就能实现同一个bt上titleLabel与image互换!

想要的效果:

例子

实际效果:哈哈,需要各位大佬们自己去美化

自定义bt层级关系

正面效果

传送门:https://github.com/JonesCxy/UIButton
不废话,直接上代码:
category.h

#import <UIKit/UIKit.h>@interface UIButton (Layout)@property (nonatomic,assign) CGRect titleRect;@property (nonatomic,assign) CGRect imageRect;@end

category.m

#import "UIButton+Layout.h"#import <objc/runtime.h>@interface UIButton ()@end@implementation UIButton (Layout)#pragma mark - ************* 通过运行时动态添加关联 ******************//定义关联的Keystatic const char * titleRectKey = "yl_titleRectKey";- (CGRect)titleRect {    return [objc_getAssociatedObject(self, titleRectKey) CGRectValue];}- (void)setTitleRect:(CGRect)rect {    objc_setAssociatedObject(self, titleRectKey, [NSValue valueWithCGRect:rect], OBJC_ASSOCIATION_RETAIN);}//定义关联的Keystatic const char * imageRectKey = "yl_imageRectKey";- (CGRect)imageRect {    NSValue * rectValue = objc_getAssociatedObject(self, imageRectKey);    return [rectValue CGRectValue];}- (void)setImageRect:(CGRect)rect {    objc_setAssociatedObject(self, imageRectKey, [NSValue valueWithCGRect:rect], OBJC_ASSOCIATION_RETAIN);}#pragma mark - ************* 通过运行时动态替换方法 ******************+ (void)load {    MethodSwizzle(self,@selector(titleRectForContentRect:),@selector(override_titleRectForContentRect:));    MethodSwizzle(self,@selector(imageRectForContentRect:),@selector(override_imageRectForContentRect:));}void MethodSwizzle(Class c,SEL origSEL,SEL overrideSEL){    Method origMethod = class_getInstanceMethod(c, origSEL);    Method overrideMethod= class_getInstanceMethod(c, overrideSEL);    //运行时函数class_addMethod 如果发现方法已经存在，会失败返回，也可以用来做检查用:    if(class_addMethod(c, origSEL, method_getImplementation(overrideMethod),method_getTypeEncoding(overrideMethod)))    {        //如果添加成功(在父类中重写的方法)，再把目标类中的方法替换为旧有的实现:        class_replaceMethod(c,overrideSEL, method_getImplementation(origMethod), method_getTypeEncoding(origMethod));    }    else    {        //addMethod会让目标类的方法指向新的实现，使用replaceMethod再将新的方法指向原先的实现，这样就完成了交换操作。        method_exchangeImplementations(origMethod,overrideMethod);    }}- (CGRect)override_titleRectForContentRect:(CGRect)contentRect {    if (!CGRectIsEmpty(self.titleRect) && !CGRectEqualToRect(self.titleRect, CGRectZero)) {        return self.titleRect;    }    return [self override_titleRectForContentRect:contentRect];}- (CGRect)override_imageRectForContentRect:(CGRect)contentRect {    if (!CGRectIsEmpty(self.imageRect) && !CGRectEqualToRect(self.imageRect, CGRectZero)) {        return self.imageRect;    }    return [self override_imageRectForContentRect:contentRect];}- (void)setTitleRect:(CGRect )titleRect ImageRect:(CGRect )imageRect {    self.titleRect = titleRect;    self.imageRect = imageRect;}@end

自定义Bt.h

#import <UIKit/UIKit.h>@interface CxyButton : UIButton@property(assign,nonatomic)CGRect titleRect;@property(assign,nonatomic)CGRect imageRect;@end

自定义Bt.m

#import "CxyButton.h"@implementation CxyButton- (instancetype)initWithFrame:(CGRect)frame{    self = [super initWithFrame:frame];    if (self) {    }    return self;}-(CGRect)titleRectForContentRect:(CGRect)contentRect{    if (!CGRectIsEmpty(self.titleRect) && !CGRectEqualToRect(self.titleRect, CGRectZero)) {        return self.titleRect;    }    return [super titleRectForContentRect:contentRect];}-(CGRect)imageRectForContentRect:(CGRect)contentRect{    if (!CGRectIsEmpty(self.imageRect)&&!CGRectEqualToRect(self.imageRect, CGRectZero)) {        return self.imageRect;    }    return [super imageRectForContentRect:contentRect];}@end

ViewControll.m

- (void)viewDidLoad {    [super viewDidLoad];    CxyButton *bt = [CxyButton buttonWithType:(UIButtonTypeCustom)];    bt.imageRect = CGRectMake(0, 0, 20, 20);    bt.titleRect = CGRectMake(20, 0, 80, 20);    bt.frame = CGRectMake(100, 100, 100, 20);    [bt setImage:[UIImage imageNamed:@"heart-1"] forState:(UIControlStateNormal)];    [bt setTitle:@"我就是我" forState:(UIControlStateNormal)];    bt.backgroundColor = [UIColor redColor];    [self.view addSubview:bt];    CxyButton *bt2 = [CxyButton buttonWithType:(UIButtonTypeCustom)];    bt2.imageRect = CGRectMake(0, 0, 30, 30);    bt2.titleRect = CGRectMake(0, 20, 30, 80);    bt2.frame = CGRectMake(100, 150, 30, 100);    [bt2 setImage:[UIImage imageNamed:@"heart-2"] forState:(UIControlStateNormal)];    [bt2 setTitle:@"我" forState:(UIControlStateNormal)];    bt2.backgroundColor = [UIColor greenColor];    [self.view addSubview:bt2];}

简介:利用运行时将bt的titleLabel与image位置动态改变,在给bt赋值时,只需要重写title与image的rect即可.