如何在swift中将Hijri(伊斯兰日历)字符串更改为公历日期

import Foundation

func convertHijriToGregorian(hijriDateString: String) -> String? {
    let hijriFormatter = DateFormatter()
    hijriFormatter.calendar = Calendar(identifier: .islamicCivil)
    hijriFormatter.dateFormat = "yyyy-MM-dd"
    
    let gregorianFormatter = DateFormatter()
    gregorianFormatter.calendar = Calendar(identifier: .gregorian)
    gregorianFormatter.dateFormat = "yyyy-MM-dd"
    
    if let hijriDate = hijriFormatter.date(from: hijriDateString) {
        let gregorianDate = gregorianFormatter.string(from: hijriDate)
        return gregorianDate
    }
    
    return nil
}

let hijriDateString = "1443-02-01"
if let gregorianDateString = convertHijriToGregorian(hijriDateString: hijriDateString) {
    print("Gregorian Date: \(gregorianDateString)")
} else {
    print("Invalid Hijri Date")
}