With c # to do a directory tree (can create, delete, rename)

Database table structure:

create table tree(
nd_id integer primary key not null,
nd_parent integer,
nd_text varchar(20)
)

Code file

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace tree structure database _
{
    public partial class the Form1: Form1
    {
        public the Form1 ()
        {
            the InitializeComponent ();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            //加载目录树
            gettreeview();
        }
        /// <summary>
        /// 向数据库传输数据
        /// </summary>
        /// <param name="str"></param>
        private void connect(string str)
        {
            string sqlcon = "Data Source = (local);Database = treedb; User ID =sa; PWD = ''";
            SqlConnection sqlconn = new SqlConnection(sqlcon);
            sqlconn.Open();
            SqlCommand com = new SqlCommand(str, sqlconn);
            com.ExecuteNonQuery();
            sqlconn.Close();
        }
        /// <summary>
        /// 目录树加载
        /// </summary>
        private void gettreeview()
        {
            string constr = " Data Source = (local); DataBase = treedb; User ID =sa; PWD = ''";
            SqlConnection con = new SqlConnection(constr);
            con.Open();
            string sqlstr = " select * from tree";
            SqlDataAdapter sqldataadapter = new SqlDataAdapter(sqlstr, con);
            DataSet ds = new DataSet();
            sqldataadapter.Fill(ds, "tree");
            con.Close();

            // root loading
            the TreeNode the TreeNode new new TN = ();
            tn.Text = "system folder";
            tn.Name = "0";
            tn.Tag = "0";
            TreeView1.Nodes.Add (TN);
            Treeview1 .SelectedNode = tn;

            // 加载子结点
            if (ds != null)
            {
                foreach (DataRow dr in ds.Tables[0].Rows)
                {
                    tn = new TreeNode();
                    tn.Text = dr["nd_text"].ToString();
                    tn.Name = dr["nd_id"].ToString();
                    tn.Tag = dr["nd_parent"].ToString();
                    if (treeView1.SelectedNode != tn.Tag)
                    {
                        TreeNode[] tn_temp = treeView1.Nodes.Find(dr["nd_parent"].ToString(), true);
                        if (tn_temp.Length > 0)
                        {
                        treeView1.SelectedNode = tn_temp[0];
                        }
                    }
                    TreeView1.SelectedNode.Nodes.Add (TN);
                }
            }
            // expand all root nodes and the cursor returns
            treeView1.ExpandAll ();
            treeView1.SelectedNode = treeView1.TopNode;
        }
        /// <Summary>
        // / Add node
        /// </ Summary>
        /// <param name = "SENDER"> </ param>
        /// <param name = "E"> </ param>
        Private void newToolStripMenuItem_Click (SENDER Object, EventArgs E )
        {
            the TreeNode the TreeNode new new TN = ();
            tn.Text = "New folder";
            int i = Convert.ToInt32(treeView1.SelectedNode.Name);
            treeView1.SelectedNode.Nodes.Add(tn);

            string str1, str2;
            str1 = "declare @a integer,@b integer set @a =(select max(nd_id)+1 from tree) set @b = " + i + "";
            str2 = "insert into tree(nd_id,nd_parent,nd_text) values (@a,@b,'新建文件夹') ";
            connect(str1 + str2);

            treeView1.Nodes.Clear();
            gettreeview();
        }
        /// <summary>
        /// 删除结点
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void deleteToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (treeView1.SelectedNode.IsExpanded == false)
            {
                int i = Convert.ToInt32(treeView1.SelectedNode.Name);
                treeView1.SelectedNode.Remove();

                str1 String, str2;
                str1 = "Integer DECLARE @a SET @a =" + I + "";
                str2 = "Delete Tree from WHERE nd_id @a =";
                Connect (str1 + str2);
            }
            the else
            {
                MessageBox.Show ( "this folder is not empty, you can not delete", "error!" MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }

        }
        /// <summary>
        /// 重命名结点
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void renameToolStripMenuItem_Click(object sender, EventArgs e)
        {
            treeView1.LabelEdit = true;
            treeView1.SelectedNode.BeginEdit();
        }
        /// <summary>
        /// 结点重命名后触发的事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void treeView1_AfterLabelEdit(object sender,NodeLabelEditEventArgs e)
        {
            treeView1.SelectedNode.EndEdit(true);
            treeView1.LabelEdit = false;

string nodename = e.Label;
int i = Convert.ToInt32(treeView1.SelectedNode.Name);

            str1 String, str2;
            str1 = "DECLARE @a VARCHAR (20 is) SET @a = '" + the nodename + "'";
            str2 = "Update Tree SET nd_text @a = WHERE nd_id =" + I + "";
            Connect ( + str2 str1);
        }
    }
}
----------------
Disclaimer: This article is CSDN blogger original article "unknowns 007", and follow CC 4.0 BY-SA copyright agreement, reprint Please include links to the original source and this statement.
Original link: https: //blog.csdn.net/kinwa007/article/details/2801199

With c # to do a directory tree (can create, delete, rename)

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