using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using ;
using System.Text;
using System.Web;
namespace BaiDuMapDemo.Models
{
public class Message
{
/// <summary>
/// 返回最新的排序后的信息
/// </summary>
/// <param name="datas">已经计算距离当前位置长度，但是未排序的信息</param>
/// <returns></returns>
public string SortText(string datas)
{
datas = datas.Replace("\\", "");
var ss = JsonConvert.DeserializeObject(datas);
List<NetModel> list = JsonConvert.DeserializeObject<List<NetModel>>(ss.ToString());
list = list.OrderBy(p => Convert.ToDouble(p.longs)).ToList();
string returnText = JsonConvert.SerializeObject(list);
return returnText;
}
/// <summary>
/// 微信坐标和数据库坐标比较距离,具体的操作方法
/// </summary>
/// <param name="lng"></param>
/// <param name="lat"></param>
/// <param name="lng1"></param>
/// <param name="lng2"></param>
/// <returns>dictionary中key为多少条数据，value为包含id，name，longs 的json数据</returns>
public Dictionary<int,string> HowLongToMe(double lng, double lat)
{
TestBaiduMapEntities Entities = new TestBaiduMapEntities();
List<Location> list = Entities.Location.Where(p => p.id > 1).ToList(); //数据库中Location表所有的数据
//将微信坐标转换为百度坐标
Dictionary<double, double> dic = ConvertToBaidu(lng, lat);
var retText = "[";
foreach(var item in list)
{
string howLong=CacleLong(dic.First().Key,dic.First().Value,item.Lng,item.Lat).ToString(); //计算出距离
retText += "{\"id\":\"" + item.id + "\",\"name\":\"" + item.Name + "\",\"longs\":\"" + howLong + "\"},";
}
retText += "]";
retText = retText.Replace(",]", "]");
var ss = JsonConvert.DeserializeObject(retText);
List<NetModel> listReturn = JsonConvert.DeserializeObject<List<NetModel>>(ss.ToString());
listReturn = listReturn.OrderBy(p => Convert.ToDouble(p.longs)).ToList();
string returnText = JsonConvert.SerializeObject(listReturn); //返回参数 returnText,即是dictionary中的string;
Dictionary<int, string> returnDic = new Dictionary<int, string>();
returnDic.Add(list.Count, returnText);
return returnDic;
}
/// <summary>
/// 将微信坐标转换为百度坐标
/// </summary>
/// <param name="lng"></param>
/// <param name="lat"></param>
/// <returns>百度坐标，key表示经度，value表示纬度</returns>
public Dictionary<double, double> ConvertToBaidu(double lng, double lat)
{
Dictionary<double, double> dic = new Dictionary<double, double>();
//转换前的GPS坐标
double x = 116.397428;
double y = 39.90923;
//google 坐标转百度链接 //http://api./ag/coord/convert?from=2&to=4&x=116.32715863448607&y=39.990912172420714&callback=BMap.Convertor.cbk_3694
//gps坐标的type=0
//google坐标的type=2
//baidu坐标的type=4
String path = "http://api./ag/coord/convert?from=0&to=4&x=" + x + "+&y=" + y + "&callback=BMap.Convertor.cbk_7594";
string res = SendDataByGET(path);
if (res.IndexOf("(") > 0 && res.IndexOf(")") > 0)
{
int sint = res.IndexOf("(") + 1;
int eint = res.IndexOf(")");
int ls = res.Length;
String str = res.Substring(sint, eint - sint);
int errint = res.IndexOf("error") + 7;
int enderr = res.IndexOf("error") + 8;
String err = res.Substring(errint, 1);
if ("0".Equals(err))
{
int sx = str.IndexOf(",\"x\":\"") + 6;
int sy = str.IndexOf("\",\"y\":\"");
int endy = str.IndexOf("\"}");
int sl = str.Length;
string xp = str.Substring(sx, sy - sx);
string yp = str.Substring(sy + 7, endy - sy - 7);
byte[] outputb = Convert.FromBase64String(xp);
string XStr = Encoding.Default.GetString(outputb);
outputb = Convert.FromBase64String(yp);
string YStr = Encoding.Default.GetString(outputb);
dic.Add(Convert.ToDouble(XStr), Convert.ToDouble(YStr));
}
}
return dic;
}
/// 通过GET方式发送数据
/// url
/// GET数据
/// GET容器
public string SendDataByGET(string Url)
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
request.Method = "GET";
request.ContentType = "text/html;charset=UTF-8";
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream myResponseStream = response.GetResponseStream();
StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));
string retString = myStreamReader.ReadToEnd();
myStreamReader.Close();
myResponseStream.Close();
return retString;
}
/// <summary>
/// 计算两个百度坐标的距离
/// </summary>
/// <param name="lng_a">当前位置的经度</param>
/// <param name="lat_a">当前位置的纬度</param>
/// <param name="lng_b">目标点的经度</param>
/// <param name="lat_b">目标点的纬度</param>
/// <returns></returns>
public double CacleLong(double lng_a, double lat_a, double lng_b, double lat_b)
{
double pk = 180 / 3.14169;
double a1 = lat_a / pk;
double a2 = lng_a / pk;
double b1 = lat_b / pk;
double b2 = lng_b / pk;
double t1 = Math.Cos(a1) * Math.Cos(a2) * Math.Cos(b1) * Math.Cos(b2);
double t2 = Math.Cos(a1) * Math.Sin(a2) * Math.Cos(b1) * Math.Sin(b2);
double t3 = Math.Sin(a1) * Math.Sin(b1);
double tt = Math.Acos(t1 + t2 + t3);
return 6366000 * tt;
}
}
public class NetModel
{
public int id { get; set; }
public string name { get; set; }
public string longs { get; set; }
}
}
数据库设计
id int Unchecked
Name nvarchar(500) Unchecked
Lng floatUnchecked
Lat float Unchecked
SerachText nvarchar(500) Checked
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