UIButton 扩展，利用runtime绑定block点击，图

前言

之前都用的继承的方式实现扩大点击事件，绑定block，最好还是扩展为UIButton的分类,特意整理一下。

效果图：

button扩展.gif

代码

.h

typedef NS_ENUM(NSUInteger, LXButtonEdgeInsetsStyle) {
    LXButtonEdgeInsetsStyleTop, // image在上，label在下
    LXButtonEdgeInsetsStyleLeft, // image在左，label在右
    LXButtonEdgeInsetsStyleBottom, // image在下，label在上
    LXButtonEdgeInsetsStyleRight // image在右，label在左
};


#define  Font(f) [UIFont systemFontOfSize:(f)]

typedef void (^ButtonBlock)(UIButton *button);
@interface UIButton (LXExpandBtn)

@property(nonatomic,strong)NSString *buttonId;//标识
@property(nonatomic,copy)ButtonBlock block;//添加点击事件
@property (nonatomic,assign) UIEdgeInsets hitTestEdgeInsets;//点击区域，默认为（0，0，0，0）; 负的为扩大


//frame初始化
+(UIButton *)LXButtonWithTitle:(NSString *)title  titleFont:(UIFont *)titleLabelFont Image:(UIImage *)image backgroundImage:(UIImage *)backgroundImage backgroundColor:(UIColor *)backgroundColor titleColor:(UIColor *)titleLabelColor frame:(CGRect)frame;
//约束初始化
+(UIButton *)LXButtonNoFrameWithTitle:(NSString *)title  titleFont:(UIFont *)titleLabelFont Image:(UIImage *)image backgroundImage:(UIImage *)backgroundImage backgroundColor:(UIColor *)backgroundColor titleColor:(UIColor *)titleLabelColor;

//添加block
-(void)addClickBlock:(ButtonBlock)block;


/**
 *  设置button的titleLabel和imageView的布局样式，及间距
 *
 *  @param style titleLabel和imageView的布局样式
 *  @param space titleLabel和imageView的间距
 */
- (void)layoutButtonWithEdgeInsetsStyle:(LXButtonEdgeInsetsStyle)style
                        imageTitleSpace:(CGFloat)space;

.m

#import "UIButton+LXExpandBtn.h"
#import <objc/runtime.h>

static const NSString *KEY_ButtonId = @"buttonId";

static const NSString *KEY_ButtonBlock = @"buttonBlock";


static const NSString *KEY_HitTestEdgeInsets = @"hitTestEdgeInsets";

@implementation UIButton (LXExpandBtn)


//扩大点击区域
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event
{
    if(UIEdgeInsetsEqualToEdgeInsets(self.hitTestEdgeInsets, UIEdgeInsetsZero) || !self.enabled || self.hidden)
    {
        return [super pointInside:point withEvent:event];
    }
    
    CGRect relativeFrame = self.bounds;
    CGRect hitFrame = UIEdgeInsetsInsetRect(relativeFrame, self.hitTestEdgeInsets);
    
    return CGRectContainsPoint(hitFrame, point);
}


+(UIButton *)LXButtonWithTitle:(NSString *)title titleFont:(UIFont *)titleLabelFont Image:(UIImage *)image backgroundImage:(UIImage *)backgroundImage backgroundColor:(UIColor *)backgroundColor titleColor:(UIColor *)titleLabelColor frame:(CGRect)frame
{
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    [button setImage:image forState:UIControlStateNormal];
    [button setBackgroundImage:backgroundImage forState:UIControlStateNormal];
    [button setTitle:title forState:UIControlStateNormal];
    [button setTitleColor:titleLabelColor forState:UIControlStateNormal];
    button.backgroundColor = backgroundColor;
    button.frame = frame;
    button.titleLabel.font = titleLabelFont;
    
    
    return button;
}
+(UIButton *)LXButtonNoFrameWithTitle:(NSString *)title titleFont:(UIFont *)titleLabelFont Image:(UIImage *)image backgroundImage:(UIImage *)backgroundImage backgroundColor:(UIColor *)backgroundColor titleColor:(UIColor *)titleLabelColor
{
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    [button setImage:image forState:UIControlStateNormal];
    [button setBackgroundImage:backgroundImage forState:UIControlStateNormal];
    [button setTitle:title forState:UIControlStateNormal];
    [button setTitleColor:titleLabelColor forState:UIControlStateNormal];
    button.backgroundColor = backgroundColor;
    button.titleLabel.font = titleLabelFont;
    return button;
}
//添加点击事件-
-(void)addClickBlock:(ButtonBlock)block
{
    
    self.block = block;
    [self addTarget:self action:@selector(buttonAction:) forControlEvents:UIControlEventTouchUpInside];
}
-(void)buttonAction:(UIButton *)button
{
    self.block(button);
}

- (void)layoutButtonWithEdgeInsetsStyle:(LXButtonEdgeInsetsStyle)style
                        imageTitleSpace:(CGFloat)space
{
    //    self.backgroundColor = [UIColor cyanColor];
    
    /**
     *  前置知识点：titleEdgeInsets是title相对于其上下左右的inset，跟tableView的contentInset是类似的，
     *  如果只有title，那它上下左右都是相对于button的，image也是一样；
     *  如果同时有image和label，那这时候image的上左下是相对于button，右边是相对于label的；title的上右下是相对于button，左边是相对于image的。
     */
    
    
    // 1. 得到imageView和titleLabel的宽、高
    CGFloat imageWith = self.imageView.frame.size.width;
    CGFloat imageHeight = self.imageView.frame.size.height;
    
    CGFloat labelWidth = 0.0;
    CGFloat labelHeight = 0.0;
    if ([UIDevice currentDevice].systemVersion.floatValue >= 8.0) {
        // 由于iOS8中titleLabel的size为0，用下面的这种设置
        labelWidth = self.titleLabel.intrinsicContentSize.width;
        labelHeight = self.titleLabel.intrinsicContentSize.height;
    } else {
        labelWidth = self.titleLabel.frame.size.width;
        labelHeight = self.titleLabel.frame.size.height;
    }
    
    // 2. 声明全局的imageEdgeInsets和labelEdgeInsets
    UIEdgeInsets imageEdgeInsets = UIEdgeInsetsZero;
    UIEdgeInsets labelEdgeInsets = UIEdgeInsetsZero;
    
    // 3. 根据style和space得到imageEdgeInsets和labelEdgeInsets的值
    switch (style) {
        case LXButtonEdgeInsetsStyleTop:
        {
            imageEdgeInsets = UIEdgeInsetsMake(-labelHeight-space/2.0, 0, 0, -labelWidth);
            labelEdgeInsets = UIEdgeInsetsMake(0, -imageWith, -imageHeight-space/2.0, 0);
        }
            break;
        case LXButtonEdgeInsetsStyleLeft:
        {
            imageEdgeInsets = UIEdgeInsetsMake(0, -space/2.0, 0, space/2.0);
            labelEdgeInsets = UIEdgeInsetsMake(0, space/2.0, 0, -space/2.0);
        }
            break;
        case LXButtonEdgeInsetsStyleBottom:
        {
            imageEdgeInsets = UIEdgeInsetsMake(0, 0, -labelHeight-space/2.0, -labelWidth);
            labelEdgeInsets = UIEdgeInsetsMake(-imageHeight-space/2.0, -imageWith, 0, 0);
        }
            break;
        case LXButtonEdgeInsetsStyleRight:
        {
            imageEdgeInsets = UIEdgeInsetsMake(0, labelWidth+space/2.0, 0, -labelWidth-space/2.0);
            labelEdgeInsets = UIEdgeInsetsMake(0, -imageWith-space/2.0, 0, imageWith+space/2.0);
        }
            break;
        default:
            break;
    }
    
    // 4. 赋值
    self.titleEdgeInsets = labelEdgeInsets;
    self.imageEdgeInsets = imageEdgeInsets;
}
#pragma mark--- getter setter--
//分类中不能直接使用setter和getter、需要使用运行时
- (void)setHitTestEdgeInsets:(UIEdgeInsets)hitTestEdgeInsets
{
    NSValue *value = [NSValue value:&hitTestEdgeInsets withObjCType:@encode(UIEdgeInsets)];
    objc_setAssociatedObject(self, &KEY_HitTestEdgeInsets, value, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

- (UIEdgeInsets)hitTestEdgeInsets
{
    NSValue *value = objc_getAssociatedObject(self, &KEY_HitTestEdgeInsets);
    if(value)
    {
        UIEdgeInsets edgeInsets;
        [value getValue:&edgeInsets];
        return edgeInsets;
    }
    else
    {
        return UIEdgeInsetsZero;
    }
}
-(void)setButtonId:(NSString *)buttonId{
    objc_setAssociatedObject(self, &KEY_ButtonId, buttonId, OBJC_ASSOCIATION_RETAIN);
}
-(NSString *)buttonId{
    return objc_getAssociatedObject(self, &KEY_ButtonId);
    
}
-(void)setBlock:(ButtonBlock)block{
    objc_setAssociatedObject(self, &KEY_ButtonBlock, block, OBJC_ASSOCIATION_RETAIN);
}
-(ButtonBlock)block{
    return objc_getAssociatedObject(self, &KEY_ButtonBlock);
}
@end

使用

 //扩大点击区域
    UIButton *button2 =[UIButton LXButtonWithTitle:@"button2" titleFont:Font(15) Image:nil backgroundImage:nil backgroundColor:[UIColor whiteColor] titleColor:[UIColor blackColor] frame:CGRectMake(0, 0, 200, 200)];
    
    [button2 setTitleColor:[UIColor purpleColor] forState:UIControlStateHighlighted];

    [button2 setTitle:@"button2点到了" forState:UIControlStateHighlighted];
    button2.layer.borderColor =[UIColor redColor].CGColor;
    button2.layer.borderWidth = 5;
    button2.center = CGPointMake(125, 125);
    
    button2.hitTestEdgeInsets =UIEdgeInsetsMake(-50, -50, -50, -50);
    [view addSubview:button2];
    
    [button2 addClickBlock:^(UIButton *button) {
        NSLog(@"点击了button2");
    }];
    
    
    //布局方式
    
    [self.topBtn layoutButtonWithEdgeInsetsStyle:LXButtonEdgeInsetsStyleTop imageTitleSpace:10];

demo 地址：UIButton扩展