TreeView 绑定SQL

最新推荐文章于 2021-01-30 11:27:07 发布

转载最新推荐文章于 2021-01-30 11:27:07 发布 · 167 阅读

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CC 4.0 BY-SA版权

原文链接：http://www.cnblogs.com/orc2/archive/2012/11/21/2781352.html

文章标签：

#数据库

本文介绍了一个使用C# WinForms创建的简单应用程序，该程序通过连接到SQL Server数据库并从其中检索数据来构建一个树状视图。应用程序首先创建一个包含城市信息的数据库表，并插入一些示例数据。然后，它定义了一个窗体，该窗体中包含一个TreeView控件，用于显示从数据库中检索的城市层级结构。

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代码复制粘贴就能运行。

create database CityDB
go
use CityDB
go
create table CityTB
(
    cid int primary key not null,--编号
    cname varchar(10) not null,--名称
    cparentID int not null --父节点，对应编号
);
go
select * from CityTB

insert into CityTB values(100,'中国',0)
insert into CityTB values(201,'广西',100)
insert into CityTB values(202,'广东',100)
insert into CityTB values(301,'南宁',201)
insert into CityTB values(302,'柳州',201)
insert into CityTB values(303,'桂林',201)
insert into CityTB values(304,'广州',202)
insert into CityTB values(305,'深圳',202)

C#winfom
-------------------------------------------------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
//树
namespace Tree2
{  
    //窗体
    public partial class Form1 : Form
    {
        public Form1()
        {      
            this.treeView1 = new System.Windows.Forms.TreeView();
            this.SuspendLayout();
            // treeView1
            this.treeView1.Location = new System.Drawing.Point(12, 12);
            this.treeView1.Name = "treeView1";
            this.treeView1.Size = new System.Drawing.Size(154, 137);
            this.treeView1.TabIndex = 0;
            this.treeView1.NodeMouseDoubleClick += new System.Windows.Forms.TreeNodeMouseClickEventHandler(this.treeView1_NodeMouseDoubleClick);
            // Form1
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(175, 165);
            this.Controls.Add(this.treeView1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.Load += new System.EventHandler(this.Form1_Load);
            this.ResumeLayout(false);
        }      
        //连接数据库
        public SqlConnection con = null;
        public SqlConnection ConOpen()
        {
            string sqlconstr = "server=127.0.0.1;database=CityDB;uid=sa;pwd=123";
            if (con == null)
            {
                con = new SqlConnection(sqlconstr);
                con.Open();
            }
            else if (con.State == ConnectionState.Closed)
            {
                con.Open();
            }
            else if (con.State == ConnectionState.Broken)
            {
                con.Close();
                con.Open();
            }
            return con;
       }
        //关闭连接
        public void ConClose()
        {
            if (con != null)
            {
                con.Close();
            }
        }
        //操作数据库
        public SqlDataReader RunRead(string _sqlstr)
        {
            this.ConOpen();
            SqlCommand cmd = new SqlCommand(_sqlstr, con);
            cmd.CommandType = CommandType.Text;
            SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
            return dr;
        }
        public DataSet RunDview(string _sqlstr, params SqlParameter[] value)
        {
            this.ConOpen();
            SqlDataAdapter adp = new SqlDataAdapter(_sqlstr, con);
            adp.SelectCommand.CommandType = CommandType.Text;
            adp.SelectCommand.Parameters.AddRange(value);
            DataSet ds = new DataSet();
            adp.Fill(ds);
            this.ConClose();
            return ds;
        }
        public string Sqlstr(int _i)
        {
            string sql_condiction = "";
            switch (_i)
            {
                case 1: sql_condiction = "0";
                    break;
                case 2: sql_condiction = "@nodeID";
                    break;
            }
            string sql = "select cid,cname from CityTB where cparentID=" + sql_condiction;
            return sql;
        }
        //父节点
        public List<Treev> Man()
        {
            List<Treev> listTree = new List<Treev>();
            SqlDataReader read = this.RunRead(Sqlstr(1));
            while (read.Read())
            {
                Treev tree = new Treev();
                tree.Cid = (int)read["Cid"];
                tree.Cname = read["Cname"].ToString();
                listTree.Add(tree);
            }
            this.ConClose();
            return listTree;
        }
        public void ManBind()
        {
            List<Treev> listTree = Man();
            DataView dv = new DataView();
            foreach (Treev tree in listTree)
            {
                TreeNode node = new TreeNode();
                node.Tag = tree.Cid;//这样好好获取ID
                node.Text = tree.Cname;
                node.Expand();
                treeView1.Nodes.Add(node);
                SonBind(node,(int)node.Tag);
            }
        }
        public void SonBind(TreeNode _mannode, int _nodeID)
        {
            DataSet ds = Manson(_nodeID);
            DataView dv = ds.Tables[0].DefaultView;
            foreach (DataRowView row in dv)
            {
                TreeNode node = new TreeNode();
                node.Tag = row["Cid"];
                node.Text = row["Cname"].ToString();
                node.Expand();
                //添加子节点
                _mannode.Nodes.Add(node);
                SonBind(node, (int)node.Tag);
            }
        }
        //子节点
        public DataSet Manson(int _nodeID)
        {
            SqlParameter[] pram =
            {
                new SqlParameter("@nodeID",SqlDbType.Int,0),
            };
            pram[0].Value = _nodeID;
            return RunDview(Sqlstr(2), pram);
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            treeView1.Nodes.Clear();
            ManBind();
        }
        private void treeView1_NodeMouseDoubleClick(object sender, TreeNodeMouseClickEventArgs e)
        {
            MessageBox.Show(e.Node.Tag.ToString());
        }   
    }

    //实体
    public class Treev
    {
        private int cid = 0;
        private string cname = "";
        private int cparentid = 0;
        public Treev()
        {

        }
        public int Cid
        {
            get { return cid; }
            set { cid = value; }
        }
        public string Cname
        {
            get { return cname; }
            set { cname = value; }
        }
        public int Cparentid
        {
            get { return cparentid; }
            set { cparentid = value; }
        }
    }

}

转载于:https://www.cnblogs.com/orc2/archive/2012/11/21/2781352.html