swift removePercentEncoding 不適用於 gb2312 字符串

Question

服務器返回一個經過 urlencode 函數處理的 gb2312 字符串：

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

如何將其解碼回 gb2312 字符串：

紫禁城魔咒_無限小說網_www.55x.cn.rar

Answer 1

在最近的 www 世界中，除 UTF-8 之外的其他編碼的百分比編碼不被認為是推薦的方式，因此您可能需要自己實現此類轉換。

它可能是這樣的：

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_無限小說網_www.55x.cn.rar")

Answer 2

NSString 確實在已棄用的函數中包含此功能。

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