根据搜索需求在谷歌地图上显示数据？
问题描述：
我有一个谷歌地图项目，它在evnet数据库中显示地图上的每个添加的事件，但我需要在用户按照Chif来宾或国家或类别过滤它时显示事件....... plz帮助我???
I have a google map project which is showing every added Event on the map in the evnet database but i need to show the events when users filter it by the Chif guest or country or by category.......plz help me???
答
使用System;
使用System.Collections.Generic;
使用System .Data;
使用System.Data.SqlClient;
使用ClassLibrary1;
public partial class _Default：System.Web.UI.Page
{Class1 cl = new Class1（）;
protected void Page_Load（object sender，EventArgs e）
$
//此方法用于将数据表转换为json字符串
public string ConvertDataTabletoString（ ）
{
DataTable dt = new DataTable（）;
using（SqlConnection con = new SqlConnection（Data Source = arsalan\\\ \\ sqlexpress; Initial Catalog = FindEvent; Integrated Securi ty = true））
{
使用（SqlCommand cmd = new SqlCommand（select lat = latitude，lng = longitude，ename = eventName，chiefguest fron Event， con））
{
con.Open（）;
SqlDataAdapter da = new SqlDataAdapter（cmd） ;
da.Fill（dt）;
System.Web.Script.Serialization.JavaScriptSerializer serializer = new System.Web.Script。 Serialization.JavaScriptSerializer（）;
List< dictionary>< string，>> rows = new List< dictionary>< string，>>（）;
Dictionary< string，>行;
foreach（dt.Rows中的DataRow dr）
{
row = new Dictionary< string，>（）;
foreach（DataColumn col in dt.Columns）
{
row.Add（col.ColumnName，dr [col]）;
}
rows.Add（row）;
}
返回serializer.Serialize（rows）;
}
}
}
protected void Button3_Click（object sender，EventArgs e）
{
if（DropDownList6.SelectedItem.Text ==By Country）
{
DropDownList3.DataSource = cl.showCountry（）;
DropDownList3.DataValueField =C_ID;
DropDownList3.DataTextField =C_Name;
DropDownList3.DataBind（）;
}
else if（DropDownList6.SelectedItem.Text ==按类别）
{
DropDownList3.DataSource = cl.showcategory （）;
DropDownList3.DataValueField =C_ID;
DropDownList3.DataTextField =C_Name;
DropDownList3.DataBind（）;
}
其他
{
DropDownList3.DataSource = cl.showarea（）;
DropDownList3.DataValueField =A_ID;
DropDownList3.DataTextField =A_Name;
DropDownList3.DataBind（）;
}
}
protected void Button4_Click（object sender，EventArgs e）
{
{
if（DropDownList6.SelectedItem.Text ==By Country）
{
GridView1.DataSource = cl.countryID（Convert.ToInt16（ DropDownList3.SelectedValue））;
GridView1.DataBind（）;
}
else if（DropDownList6.SelectedItem.Text ==按类别）
{
GridView1.DataSource = cl.categoryID（Convert.ToInt16（DropDownList3.SelectedValue））;
GridView1.DataBind（） ;
}
其他
{
GridView1.DataSource = cl.areaID（Convert.ToInt16（DropDownList3。 SelectedValue））;
GridView1.DataBind（）;
}
}
}
}
}
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using ClassLibrary1;
public partial class _Default : System.Web.UI.Page
{Class1 cl=new Class1();
protected void Page_Load(object sender, EventArgs e)
{
}
// This method is used to convert datatable to json string
public string ConvertDataTabletoString()
{
DataTable dt = new DataTable();
using (SqlConnection con = new SqlConnection("Data Source=arsalan\\sqlexpress;Initial Catalog=FindEvent;Integrated Security=true"))
{
using (SqlCommand cmd = new SqlCommand("select lat=latitude,lng=longitude,ename=eventName,chiefguest fron Event", con))
{
con.Open();
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(dt);
System.Web.Script.Serialization.JavaScriptSerializer serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
List<dictionary><string,>> rows = new List<dictionary><string,>>();
Dictionary<string,> row;
foreach (DataRow dr in dt.Rows)
{
row = new Dictionary<string,>();
foreach (DataColumn col in dt.Columns)
{
row.Add(col.ColumnName, dr[col]);
}
rows.Add(row);
}
return serializer.Serialize(rows);
}
}
}
protected void Button3_Click(object sender, EventArgs e)
{
if (DropDownList6.SelectedItem.Text == "By Country")
{
DropDownList3.DataSource = cl.showCountry();
DropDownList3.DataValueField = "C_ID";
DropDownList3.DataTextField = "C_Name";
DropDownList3.DataBind();
}
else if (DropDownList6.SelectedItem.Text == "By Category")
{
DropDownList3.DataSource = cl.showcategory();
DropDownList3.DataValueField = "C_ID";
DropDownList3.DataTextField = "C_Name";
DropDownList3.DataBind();
}
else
{
DropDownList3.DataSource = cl.showarea();
DropDownList3.DataValueField = "A_ID";
DropDownList3.DataTextField = "A_Name";
DropDownList3.DataBind();
}
}
protected void Button4_Click(object sender, EventArgs e)
{
{
if (DropDownList6.SelectedItem.Text == "By Country")
{
GridView1.DataSource = cl.countryID(Convert.ToInt16(DropDownList3.SelectedValue));
GridView1.DataBind();
}
else if (DropDownList6.SelectedItem.Text == "By Category")
{
GridView1.DataSource = cl.categoryID(Convert.ToInt16(DropDownList3.SelectedValue));
GridView1.DataBind();
}
else
{
GridView1.DataSource = cl.areaID(Convert.ToInt16(DropDownList3.SelectedValue));
GridView1.DataBind();
}
}
}
}
}