• 022-异步加载省市区联动


    AreaList.html

     1 <!DOCTYPE html>
     2 <html xmlns="http://www.w3.org/1999/xhtml">
     3 <head>
     4     <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
     5     <title></title>
     6     <script src="js/jquery-1.7.1.min.js"></script>
     7     <script>
     8         //action:1表示省,2表示市,3表示区
     9         $(function () {
    10             LoadPrivince();
    11 
    12             //如下代码不能正常执行,原因是:执行此代码时,要获取省的信息,但是现在省中还没有绑定上数据
    13             //LoadCity($('#provice').val());
    14 
    15             //为对象注册事件处理程序
    16             $('#provice').change(function () {
    17                 LoadCity($(this).val());
    18             });
    19 
    20             //调用事件处理程序,模拟事件触发
    21             //$('#provice').change();
    22 
    23             $('#city').change(function () {
    24                 LoadDistrict($(this).val());
    25             });
    26         });
    27 
    28         function LoadPrivince() {
    29             //这里是异步请求,只要发出去请求,这个方法就算执行完成
    30             $.getJSON(
    31                 'AreaList.ashx',
    32                 {
    33                     action: 1
    34                 },
    35                 function (data) {//{Id,Title}
    36                     //[{},{},{}...]
    37                     var province = $('#provice');
    38                     $.each(data, function (index, item) {
    39                         province.append('<option value="' + item.Id + '">' + item.Title + '</option>');
    40                     });
    41 
    42                     //执行下面代码时,表示省信息已经加载完成
    43                     //LoadCity(province.val());
    44                     province.change();
    45                 }
    46             );
    47         }
    48 
    49         function LoadCity(pid) {
    50             $.getJSON(
    51                 'AreaList.ashx',
    52                 {
    53                     action: 2,
    54                     pid: pid
    55                 },
    56                 function (data) {
    57                     var city = $('#city');
    58                     city.empty();//清除之前绑定的市信息
    59                     $.each(data, function (index, item) {
    60                         city.append('<option value="' + item.Id + '">' + item.Title + '</option>');
    61                     });
    62                     LoadDistrict(city.val());
    63                 }
    64             );
    65         }
    66 
    67         function LoadDistrict(cid) {
    68             $.getJSON(
    69                 'AreaList.ashx',
    70                 {
    71                     action: 3,
    72                     cid: cid
    73                 },
    74                 function (data) {
    75                     var district = $('#district');
    76                     district.empty();//清除原来绑定的数据
    77                     $.each(data, function (index, item) {
    78                         district.append('<option value="' + item.Id + '">' + item.Title + '</option>');
    79                     });
    80                 }
    81             );
    82         }
    83     </script>
    84 </head>
    85 <body>
    86     <select id="provice"></select>
    87     <select id="city"></select>
    88     <select id="district"></select>
    89 </body>
    90 </html>

    AreaList.ashx

     1     public class AreaList : IHttpHandler
     2     {
     3 
     4         public void ProcessRequest(HttpContext context)
     5         {
     6             context.Response.ContentType = "text/plain";
     7 
     8             int action = int.Parse(context.Request["action"]);
     9             List<AreaItem> list = new List<AreaItem>();
    10             string sql;
    11             DataTable dt;
    12             SqlParameter p;
    13             switch (action)
    14             {
    15                 case 1://查询省
    16                     sql = "select provinceId,provinceName from s_province";
    17                     list = DtToList(sql);
    18                     break;
    19                 case 2://查询市
    20                     sql = "select cityid,cityname from s_city where provinceid=@pid";
    21                     p = new SqlParameter("@pid", context.Request["pid"]);
    22                     list = DtToList(sql, p);
    23                     break;
    24                 case 3://查询区
    25                     sql = "select districtid,districtname from s_district where cityid=@cid";
    26                     p = new SqlParameter("@cid", context.Request["cid"]);
    27                     list = DtToList(sql, p);
    28                     break;
    29             }
    30 
    31             JavaScriptSerializer js = new JavaScriptSerializer();
    32             string result = js.Serialize(list);
    33             context.Response.Write(result);
    34         }
    35 
    36         public bool IsReusable
    37         {
    38             get
    39             {
    40                 return false;
    41             }
    42         }
    43 
    44         private List<AreaItem> DtToList(string sql, params SqlParameter[] ps)
    45         {
    46             DataTable dt = SqlHelper.GetList(sql, ps);
    47             List<AreaItem> list = new List<AreaItem>();
    48             foreach (DataRow row in dt.Rows)
    49             {
    50                 list.Add(new AreaItem()
    51                 {
    52                     Id = Convert.ToInt32(row[0]),
    53                     Title = row[1].ToString()
    54                 });
    55             }
    56             return list;
    57         }
    58     }
    59 
    60     public class AreaItem
    61     {
    62         public int Id { get; set; }
    63         public string Title { get; set; }
    64     }

    SqlHelper.cs

     1     public static class SqlHelper
     2     {
     3         private static string connStr =
     4             System.Configuration.ConfigurationManager.ConnectionStrings["conn"].ConnectionString;
     5 
     6         public static DataTable GetList(string sql, params SqlParameter[] ps)
     7         {
     8             using (SqlConnection conn = new SqlConnection(connStr))
     9             {
    10                 SqlDataAdapter sda = new SqlDataAdapter(sql, conn);
    11                 sda.SelectCommand.Parameters.AddRange(ps);
    12 
    13                 DataTable dt = new DataTable();
    14                 sda.Fill(dt);
    15 
    16                 return dt;
    17             }
    18         }
    19 
    20         public static int ExecuteNonQuery(string sql, params SqlParameter[] ps)
    21         {
    22             using (SqlConnection conn = new SqlConnection(connStr))
    23             {
    24                 SqlCommand cmd = new SqlCommand(sql, conn);
    25                 cmd.Parameters.AddRange(ps);
    26 
    27                 conn.Open();
    28                 return cmd.ExecuteNonQuery();
    29             }
    30         }
    31 
    32         public static object ExecuteScalar(string sql, params SqlParameter[] ps)
    33         {
    34             using (SqlConnection conn = new SqlConnection(connStr))
    35             {
    36                 SqlCommand cmd = new SqlCommand(sql, conn);
    37                 cmd.Parameters.AddRange(ps);
    38 
    39                 conn.Open();
    40                 return cmd.ExecuteScalar();
    41             }
    42         }
    43 
    44     }

    Web.config

     1 <?xml version="1.0" encoding="utf-8"?>
     2 
     3 <!--
     4   有关如何配置 ASP.NET 应用程序的详细信息,请访问
     5   http://go.microsoft.com/fwlink/?LinkId=169433
     6   -->
     7 
     8 <configuration>
     9   <system.web>
    10     <compilation debug="true" targetFramework="4.5" />
    11     <httpRuntime targetFramework="4.5" />
    12   </system.web>
    13   <connectionStrings>
    14     <add name="conn" connectionString="server=.;database=web1;uid=sa;pwd=123"/>
    15   </connectionStrings>
    16 </configuration>
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  • 原文地址:https://www.cnblogs.com/ninghongkun/p/6348045.html
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