主要使用递归实现，数据库结构：
最终样式：
1
protected void Page_Load(object sender, EventArgs e)
2
{
3
if (!Page.IsPostBack)
4
{
5 BindDrpClass();
6
}
7
}
8 //绑定顶级分类
9 private void BindDrpClass()
10 {
11 Bll.Class classSystem = new Bll.Class();
12 DataTable dt = classSystem.GetClassList("").Tables[0];
13 ddlClass.Items.Clear();
14 ddlClass.Items.Add(new ListItem("添加根栏目","0"));
15 DataRow[] drs = dt.Select("ParentID= " + 0);
16
17 foreach (DataRow dr in drs)
18 {
19 string classid = dr["ClassID"].ToString();
20 string classname = dr["ClassName"].ToString();
21 //顶级分类显示形式
22 classname = "╋" + classname;
23
24 ddlClass.Items.Add(new ListItem(classname, classid));
25 int sonparentid = int.Parse(classid);
26 string blank = "├";
27 //递归子分类方法
28 BindNode(sonparentid, dt, blank);
29 }
30 ddlClass.DataBind();
31 }
32 //绑定子分类
33 private void BindNode(int parentid, DataTable dt, string blank)
34 {
35 DataRow[] drs = dt.Select("ParentID= " + parentid);
36
37 foreach (DataRow dr in drs)
38 {
39 string classid = dr["ClassID"].ToString();
40 string classname = dr["ClassName"].ToString();
41
42 classname = blank + classname;
43 ddlClass.Items.Add(new ListItem(classname, classid));
44
45 int sonparentid = int.Parse(classid);
46 string blank2 = blank + "─";
47
48 BindNode(sonparentid, dt, blank2);
49 }
50 }
源码下载：
https://files.cnblogs.com/chensubo/RecursionDemo.rar
改造过的函数
// <asp:DropDownList ID="editparentid" runat="server" ></asp:DropDownList>
/// <summary>
/// 加载页面
///</summary>
protected void Page_Load(object sender, EventArgs e)
{
BindDrpClass(editparentid);}
/// <summary>
/// 创建树
/// </summary>
public void BindDrpClass(DropDownList ddlClass)
{
DataTable dt = DbHelper.ExecuteDataset(SysConst.DBNAME_XIAOWU, "select * from NT_Clcs_ClientType").Tables[0];
ddlClass.Items.Clear();
ddlClass.Items.Add(new ListItem("添加根栏目", "0"));
DataRow[] drs = dt.Select("ParentID= " + 0);
foreach (DataRow dr in drs){
string classid = dr["Cc_ID"].ToString();
string classname = dr["Cc_Name"].ToString();
//顶级分类显示形式
classname = "╋" + classname;
ddlClass.Items.Add(new ListItem(classname, classid));
int sonparentid = int.Parse(classid);
string blank = "├";
//递归子分类方法
BindNode(ddlClass, sonparentid, dt, blank);
}
editparentid.DataBind();
}
/// <summary>
/// 创建树结点
/// </summary>
private void BindNode(DropDownList ddlNode, int parentid, DataTable dt, string blank)
{
DataRow[] drs = dt.Select("ParentID= " + parentid);
foreach (DataRow dr in drs){
string classid = dr["Cc_ID"].ToString();
string classname = dr["Cc_Name"].ToString();
classname = blank + classname;
ddlNode.Items.Add(new ListItem(classname, classid));
int sonparentid = int.Parse(classid);
string blank2 = blank + "─";
BindNode(ddlNode,sonparentid, dt, blank2);
}
}
二次改造做成一个通用的类 调用 如： new DrpGradingList("select * from dbo.NT_Clcs_ClientType ", "Cc_Name", "Cc_ID", defValue).BindDrpClass(ddl);
/// <summary>
/// DropDownList 树形显示
/// </summary>
public class DrpGradingList
{
private string Sql = "";
private string Text = "";
private string Value = "";
private string defValue = "";
private string parentId = "ParentID";
/// <summary>
/// DropDownList 树形显示
/// </summary>
/// <param name="sql">SQL语句</param>
/// <param name="text">显示的文本（ 数据库字段）</param>
/// <param name="value">显示的文本对应的值（ 数据库字段）</param>
public DrpGradingList(string sql, string text, string value, string defvalue)
{
this.Sql = sql;
this.Text = text;
this.Value = value;
this.defValue = defvalue;
}
/// <summary>
/// DropDownList 树形显示
/// </summary>
/// <param name="sql">SQL语句</param>
/// <param name="text">显示的文本（ 数据库字段）</param>
/// <param name="value">显示的文本对应的值（ 数据库字段）</param>
public DrpGradingList(string sql, string text, string value, string defvalue,string pid)
{
this.Sql = sql;
this.Text = text;
this.Value = value;
this.defValue = defvalue;
this.parentId = pid;
}
/// <summary>
/// 创建树
/// </summary>
public void BindDrpClass(DropDownList ddlClass)
{
DataTable dt = DbHelper.ExecuteDataset(SysConst.DBNAME_XIAOWU, Sql).Tables[0];
ddlClass.Items.Clear();
ddlClass.Items.Add(new ListItem("顶级栏目", "0"));
DataRow[] drs = dt.Select(""+this.parentId+"= " + 0);
foreach (DataRow dr in drs)
{
string classid = dr[this.Value].ToString();
string classname = dr[this.Text].ToString();
//顶级分类显示形式
classname = "╋" + classname;
ListItem itme = new ListItem();
itme.Text=classname;
itme.Value=classid;
if (itme.Value.Equals(this.defValue))
itme.Selected = true;
ddlClass.Items.Add(itme);
int sonparentid = int.Parse(classid);
string blank = "├";
//递归子分类方法
BindNode(ddlClass, sonparentid, dt, blank);
}
ddlClass.SelectedIndex = ddlClass.Items.IndexOf(ddlClass.Items.FindByValue(this.defValue));
ddlClass.DataBind();
}
/// <summary>
/// 创建树 ddlClass.Items.Add(new ListItem("顶级栏目", "0"));
/// </summary>
public void BindDrpClass(DropDownList ddlClass, bool defItem)
{
DataTable dt = DbHelper.ExecuteDataset(SysConst.DBNAME_XIAOWU, Sql).Tables[0];
ddlClass.Items.Clear();
if (defItem){
ddlClass.Items.Add(new ListItem("顶级栏目", "0"));
}
DataRow[] drs = dt.Select("" + this.parentId + "= " + 0);
foreach (DataRow dr in drs)
{
string classid = dr[this.Value].ToString();
string classname = dr[this.Text].ToString();
//顶级分类显示形式
classname = "╋" + classname;
ListItem itme = new ListItem();
itme.Text = classname;
itme.Value = classid;
if (itme.Value.Equals(this.defValue))
itme.Selected = true;
ddlClass.Items.Add(itme);
int sonparentid = int.Parse(classid);
string blank = "├";
//递归子分类方法
BindNode(ddlClass, sonparentid, dt, blank);
}
ddlClass.SelectedIndex = ddlClass.Items.IndexOf(ddlClass.Items.FindByValue(this.defValue));
ddlClass.DataBind();
}
public void BindDrpClass(DropDownList ddlClass, bool defItem,string parentIdefVale)
{
if (parentIdefVale.Length == 0) parentIdefVale = "0";
DataTable dt = DbHelper.ExecuteDataset(SysConst.DBNAME_XIAOWU, Sql).Tables[0];
ddlClass.Items.Clear();
if (defItem)
{
ddlClass.Items.Add(new ListItem("顶级栏目", "0"));
}
DataRow[] drs = dt.Select("" + this.parentId + "= " + parentIdefVale);
foreach (DataRow dr in drs)
{
string classid = dr[this.Value].ToString();
string classname = dr[this.Text].ToString();
//顶级分类显示形式
classname = "╋" + classname;
ListItem itme = new ListItem();
itme.Text = classname;
itme.Value = classid;
if (itme.Value.Equals(this.defValue))
itme.Selected = true;
ddlClass.Items.Add(itme);
int sonparentid = int.Parse(classid);
string blank = "├";
//递归子分类方法
BindNode(ddlClass, sonparentid, dt, blank);
}
ddlClass.SelectedIndex = ddlClass.Items.IndexOf(ddlClass.Items.FindByValue(this.defValue));
ddlClass.DataBind();
}
/// <summary>
/// 创建树结点
/// </summary>
private void BindNode(DropDownList ddlNode, int parentid, DataTable dt, string blank)
{
DataRow[] drs = dt.Select(""+this.parentId+"= " + parentid);
foreach (DataRow dr in drs)
{
string classid = dr[this.Value].ToString();
string classname = dr[this.Text].ToString();
classname = blank + classname;
ListItem itme = new ListItem();
itme.Text = classname;
itme.Value = classid;
if (itme.Value.Equals(this.defValue))
itme.Selected = true;
ddlNode.Items.Add(itme);
int sonparentid = int.Parse(classid);
string blank2 = blank + "─";
BindNode(ddlNode, sonparentid, dt, blank2);
}
}
}
RadTreeView控件 应用：
<telerik:RadTreeView runat="server" ID="RadTreeView2" Skin="Office2007"
Width="300px" Height="450px" CheckBoxes="True" DataTextField="ParentID"
TriStateCheckBoxes="False">
</telerik:RadTreeView>
AddTree("0", this.RadTreeView2.Nodes);
public void AddTree(string fdm, RadTreeNodeCollection nodes)
{
DataTable dt = DbHelper.ExecuteDataset(SysConst.DBNAME_XIAOWU, "select * from NT_Clcs_Village where ParentID=" + fdm + "").Tables[0];
foreach (DataRow dr in dt.Rows)
{
string classid = dr["Cv_ID"].ToString();
string classname = dr["Cv_Name"].ToString();
RadTreeNode main = new RadTreeNode();
main.Text = classname;
main.Value = classid;
nodes.Add(main);
AddTree(classid, main.Nodes);
}
}
其它：
dropDownList.SelectedIndex=dropDownList.Items.IndexOf(dropDownList.Items.FindByText(entityBase.Bugstatus));
MVC树形：
使用： @Html.DropDownList("ddlXzqy", ViewData["ddlXzqy"] as IEnumerable<SelectListItem>)
/// <summary>
/// 创建树
/// </summary>
public void BindDrpClass(Guid selectId)
{
var list = repo.GetXzqyRootsList();
List<SelectListItem> selitem = new List<SelectListItem>();
foreach (var item in list)
{
if (selectId == item.ID)
{
selitem.Add(new SelectListItem { Text = "╋" + item.Name, Value = item.ID.ToString(), Selected = true });
this.ViewData["selected"] = item.ID.ToString();
}
else
{
selitem.Add(new SelectListItem { Text = "╋" + item.Name, Value = item.ID.ToString() });
}
string blank = "├";
BindNode(item.ID, blank, selitem, selectId);
}
selitem.Insert(0, new SelectListItem { Text = "==行政区域==", Value = "-1" });
ViewData["ddlXzqy"] = selitem;
}
private void BindNode(Guid parentid, string blank, List<SelectListItem> selitem, Guid selectId)
{
var list = repo.GetXzqyChildList(parentid);
foreach (var item in list)
{
if (selectId == item.ID)
{
selitem.Add(new SelectListItem { Text = blank + item.Name, Value = item.ID.ToString(), Selected = true });
this.ViewData["selected"] = item.ID.ToString();
}
else
{
selitem.Add(new SelectListItem { Text = blank + item.Name, Value = item.ID.ToString() });
}
string blank2 = blank + "─";
BindNode(item.ID, blank2, selitem, selectId);
}
}
此内容由惯性聚合(RSS阅读器)自动聚合整理，仅供阅读参考。 原文来自 — 版权归原作者所有。