UIView的阴影和圆角，一般情况因为不能共存，每次写这个一大坨，封装了下，原理就是view后面再加一个专门显示阴影和圆角的View。
嗯，滚动视图用的时候小心点。

看起来代码简单多了:

 UIButton * button = [UIButton buttonWithType:0];
    [button setTitle:@"尿你一脸" forState:0];
    button.frame = CGRectMake(150, 500, 160, 60);
    button.backgroundColor = [UIColor orangeColor];
    [button addTarget:self action:@selector(btnClick) forControlEvents:1<<6];
    [self.view addSubview:button];
    //或者
     [button addCornersAndShadow];
    //或者
    [button addCorners:UIRectCornerTopRight|UIRectCornerBottomRight rRadii:30.0f shadowLayer:^(CALayer * _Nonnull shadowLayer) {
        shadowLayer.shadowOpacity = 0.5;
        shadowLayer.shadowOffset = CGSizeMake(5, 5);
        shadowLayer.shadowRadius = 10;
    }];

效果图

封装成了个UIView的Category

//
//  UIView+CornerShadow.h
//  testDmoe2
//
//  Created by 马致远尿你 on 2019/12/20.
//  Copyright © 2019 马致远尿你. All rights reserved.
//

#import <UIKit/UIKit.h>

NS_ASSUME_NONNULL_BEGIN

//滚动视图里面用小心，用法看.m文件代码
@interface UIView (CornerShadow)

- (void)addCornersAndShadow;

- (void)addCorners:(UIRectCorner)corners
       shadowLayer:(void (^)(CALayer * shadowLayer))shadowLayer;

- (void)addCorners:(UIRectCorner)corners
            rRadii:(CGFloat)rRadii;

/*
@param corners 圆角设置
@param rRadii 圆角设置
@return shadowLayer 阴影设置
*/
- (void)addCorners:(UIRectCorner)corners
            rRadii:(CGFloat)rRadii
       shadowLayer:(nullable void (^)(CALayer * shadowLayer))shadowLayer;

@end

NS_ASSUME_NONNULL_END

//
//  UIView+CornerShadow.m
//  testDmoe2
//
//  Created by 马致远尿你 on 2019/12/20.
//  Copyright © 2019 马致远尿你. All rights reserved.
//

#import "UIView+CornerShadow.h"

static CGFloat rRadii = 8.0f;//默认圆角大小

@implementation UIView (CornerShadow)

- (void)addCornersAndShadow {
    [self addCorners:UIRectCornerAllCorners rRadii:rRadii shadowLayer:NULL];
}

- (void)addCorners:(UIRectCorner)corners
       shadowLayer:(void (^)(CALayer * shadowLayer))shadowLayer{
    
    [self addCorners:corners rRadii:rRadii shadowLayer:shadowLayer];
}
- (void)addCorners:(UIRectCorner)corners
            rRadii:(CGFloat)rRadii{
    
    [self addCorners:corners rRadii:rRadii shadowLayer:^(CALayer * shadowLayer) {
        shadowLayer.shadowOpacity = 0.25;
        shadowLayer.shadowOffset = CGSizeZero;
        shadowLayer.shadowRadius = 10;
    }];
}

- (void)addCorners:(UIRectCorner)corners
            rRadii:(CGFloat)rRadii
       shadowLayer:(nullable void (^)(CALayer * shadowLayer))shadowLayer{
    
    UIView * aview = self;
    CGSize cornerRadii = CGSizeMake(rRadii, rRadii);
    
    //前面的裁剪
    CAShapeLayer *mask = [CAShapeLayer layer];
    mask.path = [UIBezierPath bezierPathWithRoundedRect:aview.bounds
    byRoundingCorners:corners cornerRadii:cornerRadii].CGPath;
    aview.layer.mask = mask;
   
    //后面的那个
    if(!aview.superview) return;
    UIView * draftView = [[UIView alloc] initWithFrame:aview.frame];
    draftView.backgroundColor = aview.backgroundColor;
    [aview.superview insertSubview:draftView belowSubview:aview];
    
    if(shadowLayer){
        shadowLayer(draftView.layer);
    }else{
        draftView.layer.shadowOpacity = 0.25;
        draftView.layer.shadowOffset = CGSizeZero;
        draftView.layer.shadowRadius = 10;
    }
    
    draftView.backgroundColor = nil;
    draftView.layer.masksToBounds = NO;
    
    CALayer *cornerLayer = [CALayer layer];
    cornerLayer.frame = draftView.bounds;
    cornerLayer.backgroundColor = aview.backgroundColor.CGColor;

    CAShapeLayer *lay = [CAShapeLayer layer];
    lay.path = [UIBezierPath bezierPathWithRoundedRect:aview.bounds
    byRoundingCorners:corners cornerRadii:cornerRadii].CGPath;
    cornerLayer.mask = lay;
    [draftView.layer addSublayer:cornerLayer];
}

@end

记录下，希望能帮到有需要的童鞋~