layer 边框阴影

UIImageView* baseView = [[UIImageView alloc] init];

        baseView.backgroundColor = [UIColor whiteColor];

        //设置卡片阴影

        baseView.layer.shadowColor = RGBACOLOR(42, 47, 59, 0.3).CGColor;

        baseView.layer.shadowOffset = CGSizeMake(0, 2);

        baseView.layer.shadowOpacity = 0.5;

        baseView.layer.shadowRadius = 8;

        baseView.layer.cornerRadius = 5;

        //[baseView setImage:[UIImage imageNamed:@"home_cark_bg"]];

        [self addSubview:baseView];

//
//  UIView+LXShadowPath.h
//  LXViewShadowPath
//
//  Created by chenergou on 2017/11/23.
//  Copyright © 2017年 漫漫. All rights reserved.
//

#import <UIKit/UIKit.h>
typedef enum :NSInteger{

    LXShadowPathLeft,

    LXShadowPathRight,

    LXShadowPathTop,

    LXShadowPathBottom,

    LXShadowPathNoTop,

    LXShadowPathAllSide

} LXShadowPathSide;
@interface UIView (LXShadowPath)

/*
 * shadowColor 阴影颜色
 *
 * shadowOpacity 阴影透明度，默认0
 *
 * shadowRadius  阴影半径，默认3
 *
 * shadowPathSide 设置哪一侧的阴影，

 * shadowPathWidth 阴影的宽度，

 */

-(void)LX_SetShadowPathWith:(UIColor *)shadowColor shadowOpacity:(CGFloat)shadowOpacity shadowRadius:(CGFloat)shadowRadius shadowSide:(LXShadowPathSide)shadowPathSide shadowPathWidth:(CGFloat)shadowPathWidth;
@end

LXShadowPath.h

//
//  UIView+LXShadowPath.m
//  LXViewShadowPath
//
//  Created by chenergou on 2017/11/23.
//  Copyright © 2017年 漫漫. All rights reserved.
//

#import "UIView+LXShadowPath.h"

@implementation UIView (LXShadowPath)
/*
 * shadowColor 阴影颜色
 *
 * shadowOpacity 阴影透明度，默认0
 *
 * shadowRadius  阴影半径，默认3
 *
 * shadowPathSide 设置哪一侧的阴影，

 * shadowPathWidth 阴影的宽度，

 */

-(void)LX_SetShadowPathWith:(UIColor *)shadowColor shadowOpacity:(CGFloat)shadowOpacity shadowRadius:(CGFloat)shadowRadius shadowSide:(LXShadowPathSide)shadowPathSide shadowPathWidth:(CGFloat)shadowPathWidth{


    self.layer.masksToBounds = NO;

    self.layer.shadowColor = shadowColor.CGColor;

    self.layer.shadowOpacity = shadowOpacity;

    self.layer.shadowRadius =  shadowRadius;

    self.layer.shadowOffset = CGSizeZero;
    CGRect shadowRect;

    CGFloat originX = 0;

    CGFloat originY = 0;

    CGFloat originW = self.bounds.size.width;

    CGFloat originH = self.bounds.size.height;


    switch (shadowPathSide) {
        case LXShadowPathTop:
            shadowRect  = CGRectMake(originX, originY - shadowPathWidth/2, originW,  shadowPathWidth);
            break;
        case LXShadowPathBottom:
            shadowRect  = CGRectMake(originX, originH -shadowPathWidth/2, originW, shadowPathWidth);
            break;

        case LXShadowPathLeft:
            shadowRect  = CGRectMake(originX - shadowPathWidth/2, originY, shadowPathWidth, originH);
            break;

        case LXShadowPathRight:
            shadowRect  = CGRectMake(originW - shadowPathWidth/2, originY, shadowPathWidth, originH);
            break;
        case LXShadowPathNoTop:
            shadowRect  = CGRectMake(originX -shadowPathWidth/2, originY +1, originW +shadowPathWidth,originH + shadowPathWidth/2 );
            break;
        case LXShadowPathAllSide:
            shadowRect  = CGRectMake(originX - shadowPathWidth/2, originY - shadowPathWidth/2, originW +  shadowPathWidth, originH + shadowPathWidth);
            break;

          }

    UIBezierPath *path =[UIBezierPath bezierPathWithRect:shadowRect];

    self.layer.shadowPath = path.CGPath;

}
@end

LXShadowPath.m