转载笔记：DropDownList无限级分类(灵活控制显示形式)

2021-09-14 03:23:41

主要使用递归实现，数据库结构：

最终样式：

protected void Page_Load(object sender, EventArgs e)
2

{
3

if (!Page.IsPostBack)
4

{
5

BindDrpClass();
6

}
7

}
8

//绑定*分类
9

private void BindDrpClass()
10

{
11

Bll.Class classSystem = new Bll.Class();
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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);
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foreach (DataRow dr in drs)
18

{
19

string classid = dr["ClassID"].ToString();
20

string classname = dr["ClassName"].ToString();
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//*分类显示形式
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classname = "╋" + classname;
23

ddlClass.Items.Add(new ListItem(classname, classid));
25

int sonparentid = int.Parse(classid);
26

string blank = "├";
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//递归子分类方法
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BindNode(sonparentid, dt, blank);
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}
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ddlClass.DataBind();
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}
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//绑定子分类
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private void BindNode(int parentid, DataTable dt, string blank)
34

{
35

DataRow[] drs = dt.Select("ParentID= " + parentid);
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foreach (DataRow dr in drs)
38

{
39

string classid = dr["ClassID"].ToString();
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string classname = dr["ClassName"].ToString();
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classname = blank + classname;
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ddlClass.Items.Add(new ListItem(classname, classid));
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int sonparentid = int.Parse(classid);
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string blank2 = blank + "─";
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BindNode(sonparentid, dt, blank2);
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}
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}

源码下载：

http://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();

            //*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("*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();

                //*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("*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("*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();

                //*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("*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();

                //*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)

{

//*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);

}

　　RecursionDemo.rar

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