在JavaScript中访问C#列表变量

本文关键字：列表 变量 访问 JavaScript | 更新日期: 2023-09-27 18:09:07

C#

public List<double> Coordinatesx = new List<Double>();
    public List<double> Coordinatesy = new List<Double>();
    protected void Page_Load(object sender, EventArgs e)
    {        
        DataTable dt = new DataTable();
         SqlConnection cnn = new SqlConnection(ConfigurationManager.ConnectionStrings["TRY"].ConnectionString);
        string query = "select x,y from Addresses";
        cnn.Open();
        SqlCommand cmd = new SqlCommand(query, cnn);
        SqlDataReader id = cmd.ExecuteReader();
        while(id.Read())
        {
            Coordinatesx.Add(Convert.ToDouble(id[0]));
            Coordinatesy.Add(Convert.ToDouble(id[1]));
         }
         cnn.Close();
   }

JAVASCRIPT

function calculateinside()
    {
         for (var j = 0; j < <%=Coordinatesx.Count%>; j++) {
             var point = new google.maps.LatLng(<%=Coordinatesx%>[j],<%=Coordinatesy%>[j]);
             if(google.maps.geometry.poly.containsLocation(point,poly)){
                 marker2 = new google.maps.Marker({
                     position: point,
                     map: map,
                     icon: 'images/point2.png',
                 });
             }
      }
    }   }

我正在尝试将变量从c#转换为javascript，我尝试过该代码，但出现了错误。

var point = new google.maps.LatLng(<%=Coordinatesx%>[j],<%=Coordinatesy%>[j]);

如何访问Coordinationsx和Coordinationsy列表的每个值？

在JavaScript中访问C#列表变量

您必须在javascript代码中生成数组：

function calculateinside()
{
     var Coordinatesx = [<%=string.Join(",", Coordinatesx)%>];
     var Coordinatesy = [<%=string.Join(",", Coordinatesy)%>];
     for (var j = 0; j < Coordinatesx.lenght; j++) {
         var point = new google.maps.LatLng(Coordinatesx[j],Coordinatesy[j]);
         if(google.maps.geometry.poly.containsLocation(point,poly)){
             marker2 = new google.maps.Marker({
                 position: point,
                 map: map,
                 icon: 'images/point2.png',
             });
         }
     }
}

如果服务器端代码中有Coordinatesx = {1,2}和Coordinatesy = {5,7}，它将生成如下的javascript：

function calculateinside()
{
     var Coordinatesx = [1,2];
     var Coordinatesy = [5,7];
     for (var j = 0; j < Coordinatesx.lenght; j++) {
         var point = new google.maps.LatLng(Coordinatesx[j],Coordinatesy[j]);
         if(google.maps.geometry.poly.containsLocation(point,poly)){
             marker2 = new google.maps.Marker({
                 position: point,
                 map: map,
                 icon: 'images/point2.png',
             });
         }
     }
}

您可以通过查看页面的html源代码来看到这一点。

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