swift removingPercentEncoding 不适用于 gb2312 字符串

swift removingPercentEncoding not work with a gb2312 string

服务器returns一个gb2312字符串,经过urlencode函数处理:

%D7%CF%BD%FB%B3%C7%C4%A7%D6%E4_%CE%DE%CF%DE%D0%A1%CB%B5%CD%F8_www.55x.cn.rar

如何解码回gb2312字符串:

紫禁城魔咒_无限小说网_www.55x.cn.rar

在最近的 www 世界中,UTF-8 以外的其他编码的百分比编码不被认为是推荐的方式,因此您可能需要自己实现这种转换。

可能是这样的:

extension String.Encoding {
    static let gb_18030_2000 = String.Encoding(rawValue: CFStringConvertEncodingToNSStringEncoding(CFStringEncoding(CFStringEncodings.GB_18030_2000.rawValue)))
}

extension String {
    func bytesByRemovingPercentEncoding(using encoding: String.Encoding) -> Data {
        struct My {
            static let regex = try! NSRegularExpression(pattern: "(%[0-9A-F]{2})|(.)", options: .caseInsensitive)
        }
        var bytes = Data()
        let nsSelf = self as NSString
        for match in My.regex.matches(in: self, range: NSRange(0..<self.utf16.count)) {
            if match.rangeAt(1).location != NSNotFound {
                let hexString = nsSelf.substring(with: NSMakeRange(match.rangeAt(1).location+1, 2))
                bytes.append(UInt8(hexString, radix: 16)!)
            } else {
                let singleChar = nsSelf.substring(with: match.rangeAt(2))
                bytes.append(singleChar.data(using: encoding) ?? "?".data(using: .ascii)!)
            }
        }
        return bytes
    }
    func removingPercentEncoding(using encoding: String.Encoding) -> String? {
        return String(data: bytesByRemovingPercentEncoding(using: encoding), encoding: encoding)
    }
}

let origStr = "%D7%CF%BD%FB%B3%C7%C4%A7%D6%E4_%CE%DE%CF%DE%D0%A1%CB%B5%CD%F8_www.55x.cn.rar"
print(origStr.removingPercentEncoding(using: .gb_18030_2000)) //->Optional("紫禁城魔咒_无限小说网_www.55x.cn.rar")

NSString 在已弃用的函数中包含此功能。

https://developer.apple.com/documentation/foundation/nsstring/1407783-replacingpercentescapes