C#递归方法实现无限级分类显示效果实例

本文实例讲述了C#递归方法实现无限级分类显示效果。分享给大家供大家参考，具体如下：

运行效果如下图所示：

具体代码如下：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="RoleDemo20150305.aspx.cs" Inherits="RoleDemo20150305" %>



  
  
  
  


  

  

    
    
    




    
  
  

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Text;
using System.Data;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class RoleDemo20150305 : System.Web.UI.Page
{
  protected void Page_Load(object sender, EventArgs e)
  {
    DataTable dt = createDT();
    DataTable dtFinal = dt.Clone();
    List list = new List();
    string userStr = GetUserData();
    if (userStr.Contains(","))
    {
      string[] strs = userStr.Split(',');
      for (int i = 0; i < strs.Length; i++)
      {
        list.Add(strs[i]);
      }
    }
    else
    {
      list.Add(userStr);
    }
    for (int i = 0; i < list.Count; i++)
    {
      string module_id = list[i];
      DataRow[] drSource = dt.Select(" module_id = '" + module_id + "'"); //最终DT是否存在该数据
      DataRow[] drExist = dtFinal.Select(" module_id = '" + module_id + "'"); //最终DT是否存在该数据
      if (drExist.Length == 0)
      {
        dtFinal.Rows.Add(drSource[0]["module_id"], GetPreTag(drSource[0]["module_level"]) + drSource[0]["module_name"], drSource[0]["module_fatherid"],
          drSource[0]["module_url"], drSource[0]["module_order"], drSource[0]["module_level"]); //添加记录
      }
      FindFatherFromDT(dt, drSource, dtFinal);
    }
    //显示方式一
    DataView dv = dtFinal.DefaultView;
    dv.Sort = "module_id asc";
    DataTable dtNeed = dv.ToTable();
    GridView1.DataSource = dtNeed;
    GridView1.DataBind();
    //显示方式二
    StringBuilder builder = new StringBuilder();
    for (int i = 0; i < dtNeed.Rows.Count; i++)
    {
      DataRow dr = dtNeed.Rows[i];
      builder.AppendLine(""
       + dr["module_name"] + "");
    }
    lt1.Text = builder.ToString();
  }
  /// 

  /// 继续追溯添加父类记录
  /// 
  /// 
  /// 
  protected void FindFatherFromDT(DataTable dt, DataRow[] drFather, DataTable dtFinal)
  {
    DataRow[] drFatherUp = dt.Select(" module_id = '" + drFather[0]["module_fatherid"] + "'");
    DataRow[] drFatherUpExist = dtFinal.Select(" module_id = '" + drFather[0]["module_fatherid"] + "'");
    if (drFatherUp.Length > 0 && drFatherUpExist.Length == 0) //该记录存在父类且父类未添加到最终DT
    {
      dtFinal.Rows.Add(drFatherUp[0]["module_id"], GetPreTag(drFatherUp[0]["module_level"]) + drFatherUp[0]["module_name"], drFatherUp[0]["module_fatherid"],
          drFatherUp[0]["module_url"], drFatherUp[0]["module_order"], drFatherUp[0]["module_level"]); //继续追溯添加父类记录
      FindFatherFromDT(dt, drFatherUp, dtFinal);
    }
  }
  #region 添加前缀
  protected string GetPreTag(object num)
  {
    string pre = string.Empty;
    int i = Convert.ToInt32(num);
    if (i < 2)
    {
    }
    else if (i == 2)
    {
      pre += "└";
    }
    else
    {
      pre += "└";
      for (int j = 0; j < i - 2; j++)
      {
        pre += "─";
      }
    }
    return pre;
  }
  #endregion
  #region 用户测试数据
  protected static string GetUserData()
  {
    DataTable dt = new DataTable();
    dt.Columns.Add("userId");
    dt.Columns.Add("userModuleOption");
    dt.Rows.Add("张三", "M01010305,M010205,M0101030301");
    return dt.Rows[0]["userModuleOption"].ToString();
  }
  #endregion
  #region 创建数据
  protected static DataTable createDT()
  {
    DataTable dt = new DataTable();
    dt.Columns.Add("module_id");
    dt.Columns.Add("module_name");
    dt.Columns.Add("module_fatherid");
    dt.Columns.Add("module_url");
    dt.Columns.Add("module_order");
    dt.Columns.Add("module_level");
    dt.Rows.Add("C1", "全国", "0", "", "1", "1");
    dt.Rows.Add("M01", "广东", "C1", "", "1", "2");
    //深圳
    dt.Rows.Add("M0101", "深圳", "M01", "3.aspx", "100", "3");
    dt.Rows.Add("M010101", "南山区", "M0101", "4.aspx", "1000", "4");
    dt.Rows.Add("M010102", "罗湖区", "M0101", "", "1001", "4");
    dt.Rows.Add("M010103", "福田区", "M0101", "", "1002", "4");
    dt.Rows.Add("M010104", "宝安区", "M0101", "", "1003", "4");
    dt.Rows.Add("M010105", "龙岗区", "M0101", "", "1004", "4");
    //深圳 - 福田区
    dt.Rows.Add("M01010301", "上梅林", "M010103", "", "1002001", "5");
    dt.Rows.Add("M01010302", "下梅林", "M010103", "", "1002002", "5");
    dt.Rows.Add("M01010303", "车公庙", "M010103", "", "1002003", "5");
    dt.Rows.Add("M01010304", "竹子林", "M010103", "", "1002004", "5");
    dt.Rows.Add("M01010305", "八卦岭", "M010103", "", "1002005", "5");
    dt.Rows.Add("M01010306", "华强北", "M010103", "", "1002006", "5");
    //深圳 - 福田区 - 车公庙
    dt.Rows.Add("M0101030301", "天安数码城", "M01010303", "", "100200301", "6");
    //广州
    dt.Rows.Add("M0102", "广州", "M01", "", "101", "3");
    dt.Rows.Add("M010201", "越秀区", "M0102", "", "1105", "4");
    dt.Rows.Add("M010202", "海珠区", "M0102", "", "1106", "4");
    dt.Rows.Add("M010203", "天河区", "M0102", "", "1107", "4");
    dt.Rows.Add("M010204", "白云区", "M0102", "", "1108", "4");
    dt.Rows.Add("M010205", "黄埔区", "M0102", "", "1109", "4");
    dt.Rows.Add("M010206", "荔湾区", "M0102", "", "1110", "4");
    dt.Rows.Add("M010207", "罗岗区", "M0102", "", "1111", "4");
    dt.Rows.Add("M010208", "南沙区", "M0102", "", "1112", "4");
    return dt;
  }
  #endregion
}

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