我需要将近5万条记录绑定到我的asp.net下拉列表中,并且必须可搜索。如何最好地实现它?是否有缓存技术,以便在滚动时加载列表?感谢建议。请给予指导。
我建议利用jQuery的自动补全插件:
https://jqueryui.com/autocomplete/
它是可配置的,并且具有开箱即用的自动完成搜索功能。它还可以使用您的远程数据源(尽管您可能考虑分页API响应):
<div>
<input type="text" value="" id="tbCountries" />
</div>
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Data.SqlClient;
[System.Web.Script.Services.ScriptService]
public class WebService : System.Web.Services.>WebService {
[WebMethod]
public List<string> ShowCountryList(string sLookUP)
{
List<string> lstCountries = new List<string>();
string sConnString = "Data Source=DNA;Persist Security Info=False;" +
"Initial Catalog=DNA_CLASSIFIED;User Id=sa;Password=;Connect Timeout=30;";
SqlConnection myConn = new SqlConnection(sConnString);
SqlCommand objComm = new SqlCommand("SELECT CountryName FROM Country " +
"WHERE CountryName LIKE '%'+@LookUP+'%' ORDER BY CountryName", myConn);
myConn.Open();
objComm.Parameters.AddWithValue("@LookUP", sLookUP);
SqlDataReader reader = objComm.ExecuteReader();
while (reader.Read()) {
lstCountries.Add(reader["CountryName"].ToString());
}
myConn.Close(); return lstCountries;
}
}
<script>
$(document).ready(function() {
BindControls();
});
function BindControls() {
$("#tbListOfCountries").autocomplete({
source: function(request, response) {
$.ajax({
url: "WebService.asmx/ShowCountryList",
data: "{ 'sLookUP': '" + request.term + "' }",
dataType: "json",
type: "POST",
contentType: "application/json; charset=utf-8",
dataFilter: function(data) { return data; },
success: function(data) {
response($.map(data.d, function(item) {
return { value: item }
}))
},
error: function(XMLHttpRequest, textStatus, errorThrown) {
alert(textStatus);
}
});
},
minLength: 1 // MINIMUM 1 CHARACTER TO START WITH.
});
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<link rel="stylesheet" href="//code.jquery.com/ui/1.12.1/themes/base/jquery-ui.css" />
<script src="https://code.jquery.com/jquery-1.12.4.js"></script>
<script src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script>
</head>
<body>
<form id="form1" runat="server">
<div class="ui-widget">
<asp:TextBox ID="txtDepartment" runat="server" ClientIDMode="Static" />
</div>
</form>
<script>
$(function () {
$("[id$=txtDepartment]").autocomplete({
source: function (request, response) {
$.ajax({
url: "FetchDropdownList.aspx/GetDepartment",
data: "{'departmentName':'" + document.getElementById('txtDepartment').value + "'}",
dataType: "json",
type: "POST",
contentType: "application/json; charset=utf-8",
dataFilter: function (data) { return data; },
success: function (data) {
response($.map(data.d, function (item) {
return {
value: item.Name
}
}))
},
error: function (XMLHttpRequest, textStatus, errorThrown) {
alert(textStatus);
}
});
},
minLength: 1
});
});
</script>
</body>
</html>
public class Department
{
public int Id { get; set; }
public string Name { get; set; }
}
private static List<Department> GetDepartment()
{
List<Department> departments = new List<Department>();
for (int i = 0; i < 10000; i++)
{
Department department = new Department();
department.Id = i;
department.Name = "Department " + i.ToString();
departments.Add(department);
}
return departments;
}
[WebMethod]
public static List<Department> GetDepartment(string departmentName)
{
int totalDepartments = GetDepartment().Count;
List<Department> departments = GetDepartment().Where(d => d.Name.ToLower().StartsWith(departmentName.ToLower())).Take(20).ToList();
return departments;
}
我看到了两个立即的解决方案。
类似于这个:
无论哪种自动完成实现都可以在您的情况下工作。
解决方案1:使用自动完成选择框
解决方案2:使用带有虚拟化的选择框
这取决于列表项来自哪里。 如果它们来自列表或数据库,只需将它们附加,然后使用JavaScript搜索列表。