private string BuildRequestMysign(Dictionary <string, string> sPara) { //把数组所有元素,按照“参数=参数值”的模式用“&”字符拼接成字符串 string prestr = Core.CreateLinkString(sPara); //把最终的字符串签名,获得签名结果 string mysign = ""; switch (_sign_type) { case "MD5": mysign = AlipayMD5.Sign(prestr, _key, _input_charset); break; default: mysign = ""; break; } return(mysign); }