地图 查经纬度 算距离

A.计算两点距离

public const double EarthRadiusKm = 6378.137; // WGS-84 

public double GetDistance(double p1Lat, double p1Lng,

                          double p2Lat, double p2Lng)

{



    double dLat1InRad = p1Lat * (Math.PI / 180);

    double dLong1InRad = p1Lng * (Math.PI / 180);

    double dLat2InRad = p2Lat * (Math.PI / 180);

    double dLong2InRad = p2Lng * (Math.PI / 180);

    double dLongitude = dLong2InRad - dLong1InRad;

    double dLatitude = dLat2InRad - dLat1InRad;

    double a = Math.Pow(Math.Sin(dLatitude / 2), 2)

                      + Math.Cos(dLat1InRad) * Math.Cos(dLat2InRad) 

                      * Math.Pow(Math.Sin(dLongitude / 2), 2);

    double c = 2 * Math.Atan2(Math.Sqrt(a), Math.Sqrt(1 - a));

    double dDistance = EarthRadiusKm * c;

    return dDistance;

}  

 

 

B.获取经纬度,

 ApiUrl: http://maps.google.co.uk/maps/geo?q= + searchkey + &output=xml

            http://maps.google.fr/maps/geo?q= + searchkey + &output=xml

 searchkey=housenum.Trim()+" "+street.Trim()+" "+city.Trim()+" "+postcode.Trim()).Replace(" ", "+")

public bool GetCoordinate(string ApiUrl, string searchkey,

                      out double logitute, out double Latitude)

{



    string xmldoc = "";

    logitute=0;

    Latitude=0;

    HttpWebRequest request;

    HttpWebResponse response = null;

    Stream stream;

    string resultStr = "0,0";

    try

    {

        request = (HttpWebRequest)WebRequest.Create(ApiUrl);

        response = (HttpWebResponse)request.GetResponse();

        stream = response.GetResponseStream();

        xmldoc = new StreamReader(stream,

                    System.Text.Encoding.Default).ReadToEnd();

        stream.Close();

        response.Close();

    }

    catch (Exception ex)

    {



    }

    //xml demo

    //<Point>

    //<coordinates>116.4074130,39.9042140,0</coordinates>

    //</Point>



    int startPosition = xmldoc.IndexOf("<coordinates>");

    int endPosition = xmldoc.IndexOf("</coordinates>");

    if (startPosition >= 0 && endPosition >= 0)

    {

        string coordi = xmldoc.Substring(startPosition,

                                endPosition - startPosition);

        int douposition = coordi.LastIndexOf(",");

        coordi = coordi.Substring(0, douposition);

        resultStr = coordi.Replace("<coordinates>", "")

                          .Replace("</coordinates>", "");

    }

    else

    {

        resultStr = "no";

    }



    if (!resultStr.Equals("no"))

    {

        var p=resultStr.Split(',');

        if (p.Length==2)

        {

            var style = NumberStyles.AllowDecimalPoint;

            var culture =CultureInfo.CreateSpecificCulture("en-GB");

            return (double.TryParse(p[0], style, culture, out logitute) 

                && double.TryParse(p[1], style, culture, out Latitude));

        }

    }

    return false;



}

 

 

 C.Google Map API V3,设置某地经纬度.

 

    var gMap;

    var gPoint;

    var gMarker;

    var gMapRegion="NL";

    var gMarkerImg= 'bg_A.png';

  function initialize() {

      

            gPoint = new google.maps.LatLng(52.3702157, 4.8951679);

        var myOptions = {

            zoom: 8,

            center:gPoint,

            mapTypeId: google.maps.MapTypeId.ROADMAP

        };

        gMap = new google.maps.Map(document.getElementById("map_canvas"), myOptions);

        gMarker = new google.maps.Marker({

        position: gPoint,

        draggable:true,

        map: gMap,

        icon: gMarkerImg

        });



  



    google.maps.event.addListener(gMap, 'rightclick', function (event) {        

        gMarker.setPosition(event.latLng)

       

    });



   

    google.maps.event.addListener(gMarker, 'position_changed', function () {

        var p = gMarker.getPosition();   

        $("#txtlat").val(p.lat().toFixed(7));

        $("#txtlng").val(p.lng().toFixed(7));

    });

    google.maps.event.addListener(gMarker, 'mouseover', function () {

        SetTipPosition(gMarker, 150, 150);

    });



    

    google.maps.event.addListener(gMarker, 'mouseout', function () {

          $("#flowerInfo").css("display","none");

      });



      function SetTipPosition(marker,tipwidth,tipheight) {

          var ne = gMap.getBounds().getNorthEast();

          var sw = gMap.getBounds().getSouthWest();

          var height = Math.abs(ne.lat() - sw.lat());

          var width = Math.abs(ne.lng() - sw.lng());



          var mp = marker.getPosition();

          var x = Math.abs(mp.lng() - sw.lng());

          var y = Math.abs(mp.lat() - ne.lat());



          var distanceMark = 10;

          var xx = 1.00 * x / width * $("#map_canvas").width() + distanceMark;

          var yy = 1.00 * y / height * $("#map_canvas").height()+ distanceMark;

          if (xx + tipwidth > $("#map_canvas").width())

              xx = xx - tipwidth - 2 * distanceMark;

          if (yy + tipheight > $("#map_canvas").height())

              yy = yy - tipheight - 2 * distanceMark;



          var content = "lat:" + marker.getPosition().lat().toFixed(7) 
                     + ",lng:" + marker.getPosition().lng().toFixed(7)
                     + ",Zoom:" + gMap.getZoom();

          ShowTip(xx + "px", yy + "px",content);

      }

 

  }





  function ShowTip(x, y, content) {    

      if ($("#flowerInfo").length == 0) {

          $("#map_canvas div:first div:first").append("<div id='flowerInfo' 
              style='z-index: 230; position: absolute;
              display:none;width:150px;height:150px;background-color:write'><b>" 
             + content + "</b></div>");

      }

      else {

         $("#flowerInfo").html("<b>"+content+"</b>")

      }

      $("#flowerInfo").css({ left: x, top: y, display: "block" });

  }



  $(function () {

      initialize();

      if ($("#txtlat").val() != '' && $("#txtlng").val() != '') {

           var p = new google.maps.LatLng($("#txtlat").val(), $("#txtlng").val())

           gMarker.setPosition(p);

           gMap.setCenter(p);         

      }

      $("#btnSearch").click(function () {

          var address = $("#txtKeyword").val();

          var geocoder = new google.maps.Geocoder();

          if (geocoder) {

              geocoder.geocode({ "address": address, "region": gMapRegion }, function (results, status) {

                  if (status == google.maps.GeocoderStatus.OK && results.length > 0 &&
                      results[0].address_components[results[0].address_components.length - 1].short_name == gMapRegion) {

                      gMarker.setPosition(results[0].geometry.location);

                      gMarker.setIcon(gMarkerImg);

                      var bounds = new google.maps.LatLngBounds();

                      for (var i = 0; i < results.length; i++) {

                          if (results[i].address_components.pop().short_name == gMapRegion)

                              bounds.union(results[i].geometry.bounds);

                      } //for

                      gMap.fitBounds(bounds);

                      gMap.setZoom((gMap.getZoom() > 10) ? gMap.getZoom() - 2 : 8);

                  } //if

                  else {

                      gMarker.setIcon();

                      gMarker.setPosition(gPoint);

                      gMap.setCenter(gPoint);

                      gMap.setZoom(8);

                  }

              });



          } // if



      }); // click

  });              //jquery

 <input id="txtKeyword" type="text" value="Hoorn"/>

 <input id="btnSearch" type="button" value="Search"/>

 <input id="txtlat" type="text" value="52.7625419"/>

 <input id="txtlng" type="text" value="6.8946796"/>

 <div id="map_canvas" style="width:100%; height:80%;" >

 </div>