csharp 解析URL参数

Posted 2021-05-12

        /// <summary>
        /// 将查询字符串解析转换为名值集合.
        /// </summary>
        /// <param name="queryString"></param>
        /// <returns></returns>
        public static NameValueCollection GetQueryString(string queryString)
        {
            return GetQueryString(queryString, null, true);
        }

        /// <summary>
        /// 将查询字符串解析转换为名值集合.
        /// </summary>
        /// <param name="queryString"></param>
        /// <param name="encoding"></param>
        /// <param name="isEncoded"></param>
        /// <returns></returns>
        public static NameValueCollection GetQueryString(string queryString, Encoding encoding, bool isEncoded)
        {
            queryString = queryString.Replace("?", "");
            NameValueCollection result = new NameValueCollection(StringComparer.OrdinalIgnoreCase);
            if (!string.IsNullOrEmpty(queryString))
            {
                int count = queryString.Length;
                for (int i = 0; i < count; i++)
                {
                    int startIndex = i;
                    int index = -1;
                    while (i < count)
                    {
                        char item = queryString[i];
                        if (item == '=')
                        {
                            if (index < 0)
                            {
                                index = i;
                            }
                        }
                        else if (item == '&')
                        {
                            break;
                        }
                        i++;
                    }
                    string key = null;
                    string value = null;
                    if (index >= 0)
                    {
                        key = queryString.Substring(startIndex, index - startIndex);
                        value = queryString.Substring(index + 1, (i - index) - 1);
                    }
                    else
                    {
                        key = queryString.Substring(startIndex, i - startIndex);
                    }
                    if (isEncoded)
                    {
                        result[MyUrlDeCode(key, encoding)] = MyUrlDeCode(value, encoding);
                    }
                    else
                    {
                        result[key] = value;
                    }
                    if ((i == (count - 1)) && (queryString[i] == '&'))
                    {
                        result[key] = string.Empty;
                    }
                }
            }
            return result;
        }

        /// <summary>
        /// 解码URL.
        /// </summary>
        /// <param name="encoding">null为自动选择编码</param>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string MyUrlDeCode(string str, Encoding encoding)
        {
            if (encoding == null)
            {
                Encoding utf8 = Encoding.UTF8;
                //首先用utf-8进行解码                     
                string code = HttpUtility.UrlDecode(str.ToUpper(), utf8);
                //将已经解码的字符再次进行编码.
                string encode = HttpUtility.UrlEncode(code, utf8).ToUpper();
                if (str == encode)
                    encoding = Encoding.UTF8;
                else
                    encoding = Encoding.GetEncoding("gb2312");
            }
            return HttpUtility.UrlDecode(str, encoding);
        }