c#之解决百度地图api APP SN校验失败问题（代码实例）-木庄网络博客

本文摘自PHP中文网，作者青灯夜游，侵删。

本篇文章给大家介绍在使用c#调用百度地图api时遇到的SN校验失败问题的解决方法。有一定的参考价值，有需要的朋友可以参考一下，希望对你们有所助。

在使用c#调用百度地图Web服务api遇到的签名（sn校验）问题，在此记录一下，（ip白名单校验的请忽略）

1.首先获取ak与sk，这个两个东西可以从控制台中获取到

2.在这个地址：sn签名算法，里面提供了java，php，c#，python2.7的参考代码

在百度提供的参考代码中，其中c#的代码中MD5加密方法是有问题的，（在笔者写随笔时，代码还是有问题的，之后希望百度官方修复此问题）

把百度的MD5方法修改一下，签名就正确了，api正常调用了，开心！！

这里是完整的签名代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web;
 
namespace IpService.Code
{
    public class BaiduAKSNCaculater
    {
        private static string MD5(string password)
        {
            try
            {
                System.Security.Cryptography.HashAlgorithm hash = System.Security.Cryptography.MD5.Create();
                byte[] hash_out = hash.ComputeHash(System.Text.Encoding.UTF8.GetBytes(password));
 
                var md5_str=BitConverter.ToString(hash_out).Replace("-", "");
                return md5_str.ToLower();
 
            }
            catch
            {
                 
                throw;
            }
        }
 
        private static string UrlEncode(string str)
        {
            str = System.Web.HttpUtility.UrlEncode(str);
            byte[] buf = Encoding.ASCII.GetBytes(str);//等同于Encoding.ASCII.GetBytes(str)
            for (int i = 0; i < buf.Length; i++)
                if (buf[i] == '%')
                {
                    if (buf[i + 1] >= 'a') buf[i + 1] -= 32;
                    if (buf[i + 2] >= 'a') buf[i + 2] -= 32;
                    i += 2;
                }
            return Encoding.ASCII.GetString(buf);//同上，等同于Encoding.ASCII.GetString(buf)
        }
 
        private static string HttpBuildQuery(IDictionary<string, string> querystring_arrays)
        {
 
            StringBuilder sb = new StringBuilder();
            foreach (var item in querystring_arrays)
            {
                sb.Append(UrlEncode(item.Key));
                sb.Append("=");
                sb.Append(UrlEncode(item.Value));
                sb.Append("&");
            }
            sb.Remove(sb.Length - 1, 1);
            return sb.ToString();
        }
 
        public static string CaculateAKSN(string ak, string sk, string url, IDictionary<string, string> querystring_arrays)
        {
            var queryString = HttpBuildQuery(querystring_arrays);
 
            var str = UrlEncode(url + "?" + queryString + sk);
            
            return MD5(str);
        }
    }
}

这里是调用代码

public static string GetIPAreas()
        {
            var ip = "你要查询的ip地址";
            var ak = "从百度控制台获取到应用AK";
            var sk = "从百度控制台获取到签名SK";
            var uri = "http://api.map.baidu.com";
            var path = "/location/ip";
            var param = new Dictionary<string, string>();
            param.Add("ip", ip);
            param.Add("ak", ak);
 
            //注意：签名的url参数，并非完整地址
            var sn = BaiduAKSNCaculater.CaculateAKSN(ak, sk, path, param);
 
            var url = string.Format("{0}{1}?ip={2}&ak={3}&sn={4}",
                uri,
                path,
                ip,
                ak,
                sn);
 
            var str = Code.HttpService.Get(url);
            return str;
        }