jQuery ajax implementation of non-refresh cascading menu example

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jQuery ajax implementation of non-refresh cascading menu example_jquery

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May 16, 2016 pm 03:58 PM

ajaxjquery

The front-end uses AJAX to directly call the background method. Some people always post questions, so I’ll give you an example

The following is a non-refresh cascading menu made by using JQUERY and AJAX in the frontend to call background methods

CasMenu.aspx page:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="CasMenu.aspx.cs" Inherits="_Default" %> 
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head id="Head1" runat="server"> 
  <title>Porschev--前台JS(Jquery)调用后台方法 级联菜单</title> 
  <script src="js/jquery-1.3.2-vsdoc.js" mce_src="js/jquery-1.3.2-vsdoc.js" type="text/javascript"></mce:script> 
  <script type="text/javascript"> 
    $(function() {       
      $("#selPro").change(function() {  //省份下拉菜单的change事件         
        var params = '{str:"' + $(this).val() + '"}'; //此处参数名要注意和后台方法参数名要一致                 
        $.ajax({           
          type: "POST",          //提交方式           
          url: "CasMenu.aspx/ShowCity",  //提交的页面/方法名           
          data: params,          //参数（如果没有参数：null）           
          dataType: "text",        //类型           
          contentType: "application/json; charset=utf-8",           
          beforeSend: function(XMLHttpRequest) {             
            $('#tipsDiv').text("正在查询...");           
          },           
          success: function(msg) {                         
            $('#tipsDiv').text("查询成功!");             
            $("#selCity option").each(function() {               
              $(this).remove();  //移除原有项             
            });             
            $("<option value='0'>===请选择===</option>").appendTo("#selCity");  //添加一个默认项             
            $(eval("(" + msg + ")").d).appendTo("#selCity");    //将返回来的项添加到下拉菜单中           
          },           
          error: function(xhr, msg, e) {             
            alert("error");           
          }         
         });       
      });     
    });   
    </script> 
</head> 
<body> 
  <form id="form1" runat="server"> 
  <div> 
    Porschev--前台JS(Jquery)调用后台方法 级联菜单<br /> 
    <br /> 
    <select id="selPro" name="selPro"> 
      <%=strPro %> 
    </select>省(直辖市) 
    <select id="selCity" name="selCity"> 
      <option value="0">===请选择===</option> 
    </select>（市） 
  </div> 
  <div id="tipsDiv"> 
  </div> 
  </form> 
</body> 
</html>

CasMenu.aspx.cs

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using CasMenuModels; 
using CasMenuBLL; 
using System.Text; 
public partial class _Default : System.Web.UI.Page  
{   
  public static string strPro = string.Empty; //省份下拉项   
  public static string strCity = string.Empty; //城市下拉项   
  protected void Page_Load(object sender, EventArgs e)   
  {     
    if (!IsPostBack)     
    {          
    }     
    ShowPro();   
  }   
   
  #region##省份下拉列表框   
  /// <summary>   
  /// 省份下拉列表框   
  /// </summary>   
  /// <returns></returns>   
  public string ShowPro()   
  {     
    StringBuilder str = new StringBuilder();    //得到所有省份集合     
    List<CasMenuModels.Province> list = new CasMenuBLL.ProvinceManager().GetAllProvince();            //添加一个初始项     
    str.Append("<option value=\"");     
    str.Append("0");     
    str.Append("\">");     
    str.Append("===请选择===");     
    str.Append("</option>");         
     
    //循环追加省份下拉项         
    foreach (CasMenuModels.Province p in list)     
    {       
      str.Append("<option value=\"");       
      str.Append(p.ProvinceId);       
      str.Append("\">");       
      str.Append(p.ProvinceName);       
      str.Append("</option>");           
    }     
    return strPro = str.ToString();   
  }   
   
  #endregion  #region##城市下拉列表框   
  /// <summary>   
  /// 城市下拉列表框   
  /// </summary>   
  /// <param name="str">省份ID</param>   
  /// <returns></returns>   
  [System.Web.Services.WebMethod()]   
  public static string ShowCity(string str)  //方法是静态的   
  {     
    StringBuilder strCi = new StringBuilder();     
    if (str == "0")   //为初始项     
    {       
      strCi.Append("<option value=\"");       
      strCi.Append("请选择");       
      strCi.Append("\">");       
      strCi.Append("请选择");       
      strCi.Append("</option>");     
    }     
    else     
    {       
      List<CasMenuModels.City> list = new CasMenuBLL.CityManager().GetAllByProId(Convert.ToInt32(str));  //根据省份ID得到城市集合       
      foreach (City c in list)       
      {         
        strCi.Append("<option value=\"");         
        strCi.Append(c.CityId);         
        strCi.Append("\">");         
        strCi.Append(c.CityName);         
        strCi.Append("</option>");               
      }     
    }     
    return strCity = strCi.ToString();   
  }   
  #endregion   
}

I have notes on everything you need to pay attention to,

Of course, there are far more ways to transfer the front-end to the back-end than this one, for example, AJAXPRO is also very useful

The above is the entire content of this article, I hope you all like it.

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