oc類擴展

//
//  UIView+Extension.h
//  畫虛線
//
//  Created by tdw on 2020/12/2.
//

#import <UIKit/UIKit.h>

NS_ASSUME_NONNULL_BEGIN

@interface UIView (Extension)
/**
 畫外框虛線
 
 @param width 虛線寬度
 @param lenth 一段虛線的長度
 @param space 虛線間距
 @param cornerRadius 邊框圓角

 */
-(void) drawBoardDottedLine:(double)width lenth:(double)lenth space:(double)space cornerRadius:(double)cornerRadius color:(UIColor*)color;
@end

NS_ASSUME_NONNULL_END
@end

//
//  UIView+Extension.m
//  畫虛線
//
//  Created by tdw on 2020/12/2.
//

#import "UIView+Extension.h"

@implementation UIView (Extension)
-(void) drawBoardDottedLine:(double)width lenth:(double)lenth space:(double)space cornerRadius:(double)cornerRadius color:(UIColor*)color
{
    self.layer.cornerRadius = cornerRadius;
    
    CAShapeLayer *borderLayer = [CAShapeLayer layer];
    
    borderLayer.bounds = self.bounds;
    borderLayer.position = CGPointMake(CGRectGetMidX(self.bounds), CGRectGetMidY(self.bounds));
    borderLayer.path = [UIBezierPath bezierPathWithRoundedRect:borderLayer.bounds cornerRadius:cornerRadius].CGPath;
    borderLayer.lineWidth = width / [[UIScreen mainScreen] scale];
    //虛線邊框---小邊框的長度
    borderLayer.lineDashPattern = @[@(lenth), @(space)];//前邊是虛線的長度，后邊是虛線之間空隙的長度
    borderLayer.lineDashPhase = 0.1;
    //實線邊框
    borderLayer.fillColor = [UIColor clearColor].CGColor;
    borderLayer.strokeColor = color.CGColor;
    [ self . layer addSublayer :borderLayer];
}
@end

swift使用使用的時候要在橋接檔案里添加：

//畫虛線-Bridging-Header.h
#import "UIView+Extension.h"

swift類擴展

//
//  UIView+Extension.swift
//  畫虛線
//
//  Created by tdw on 2020/12/2.
//

import UIKit
extension UIView{
    func swiftDrawBoardDottedLine(width:CGFloat,lenth:CGFloat,space:CGFloat,cornerRadius:CGFloat,color:UIColor){
        self.layer.cornerRadius = cornerRadius
        let borderLayer =  CAShapeLayer()
        borderLayer.bounds = self.bounds
        
        borderLayer.position = CGPoint(x: self.bounds.midX, y: self.bounds.midY);
        borderLayer.path = UIBezierPath(roundedRect: borderLayer.bounds, cornerRadius: cornerRadius).cgPath
        borderLayer.lineWidth = width / UIScreen.main.scale
        
        //虛線邊框---小邊框的長度
        
        borderLayer.lineDashPattern = [lenth,space] as? [NSNumber] //前邊是虛線的長度，后邊是虛線之間空隙的長度
        borderLayer.lineDashPhase = 0.1;
        //實線邊框
        
        borderLayer.fillColor = UIColor.clear.cgColor
        borderLayer.strokeColor = color.cgColor
        self.layer.addSublayer(borderLayer)
        
        
    }
}

在swift里面呼叫類擴展

//
//  ViewController.swift
//  畫虛線
//
//  Created by tdw on 2020/12/2.
//

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        let v1 = UIView()
        v1.frame = CGRect(x: 50, y: 50, width: 100, height: 100)
        v1.backgroundColor = UIColor.yellow
        //呼叫oc類擴展
        v1.drawBoardDottedLine(3, lenth: 5, space: 3, cornerRadius: 10, color: UIColor.red)
        view.addSubview(v1)
        
        
        let v2 = UIView()
        v2.frame = CGRect(x: 50, y: 200, width: 100, height: 100)
        v2.backgroundColor = UIColor.lightGray
        //呼叫swift類擴展
        v2.swiftDrawBoardDottedLine(width: 5, lenth: 4, space: 2, cornerRadius: 4 ,color:UIColor.orange)
        view.addSubview(v2)
        
        
    }


}

運行結果