转载笔记:DropDownList无限级分类(灵活控制显示形式)
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();
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classname = blank + classname;
43
ddlClass.Items.Add(new ListItem(classname, classid));
44
45
int sonparentid = int.Parse(classid);
46
string blank2 = blank + "─";
47
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BindNode(sonparentid, dt, blank2);
49
}
50
}
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)
{
/// 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);
}
}
/// </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);
}
}
}
/// 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>
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);
}
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)
{
//顶级分类显示形式
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() });
}
//递归子分类方法
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);
}
}

转载笔记:DropDownList无限级分类(灵活控制显示形式) 调用方式:AddTree("0", this.RadTreeView2.Nodes);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); 改造过的函数 BindDrpClass(editparentid);}
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