TreeView和ImageList

TreeView和ImageList

　　初学者因为所知道的知识有限所以有很多地方做的可能不合常理，如果大家有什么建议或想法，大家尽管说。

　数据库建表(这里用的是Oracle)

　　

      

 

　数据库操作类代码：

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.OracleClient;

namespace test
{
    class Conn
    {
        /// <summary>
        /// 创建数据库连接
        /// </summary>
        private static OracleConnection connection;
        /// <summary>
        /// 连接字符串
        /// </summary>
        public static OracleConnection Conne
        {
            get
            {
                string connectionString = "Data Source = 数据库地址;User ID=用户名;password=密码";
                if (connection == null)
                {
                    connection = new OracleConnection(connectionString);
                    connection.Open();
                }
                else if (connection.State == ConnectionState.Closed)
                {
                    connection.Open();
                }
                else if (connection.State == ConnectionState.Broken)
                {
                    connection.Close();
                    connection.Open();
                }
                return connection;
            }
        }

        /// <summary>
        /// 查询TreeView根节点
        /// </summary>
        /// <returns></returns>
        public static DataTable Select()
        {
            string sql = "select sysid,sysparentid,sysname,syslevel from t_sysinfo";
            OracleDataAdapter adapter = new OracleDataAdapter(sql, Conne);
            DataSet ds = new DataSet();
            adapter.Fill(ds);
            return ds.Tables[0];
        }
    }
}

　From窗体：

　　窗体说明：TreeView name为treeView1，ImageList为imageList1；

　　　　　　　ImageList name为imageList1；

　　窗体代码：

　

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

namespace test
{
    public partial class Form1 : Form
    {
        private DataTable dt;
        public Form1()
        {
            InitializeComponent();
            dt = Conn.Select();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            FillTreeview();
        }

        /// <summary>
        /// 生成树信息并添加根节点
        /// </summary>
        public void FillTreeview()
        {
             this.treeView1.Nodes.Clear();
             this.treeView1.ImageIndex = 0;
             this.treeView1.ImageList = this.imageList1;
             DataRow[] dr = dt.Select("syslevel = '0'");
             for (int i = 0; i < dr.Length; i++)
             {
                 string parentid = dr[i]["sysid"].ToString();
                 string nodename = dr[i]["sysname"].ToString();
                 TreeNode rootnode = new TreeNode();
                 rootnode.Text = nodename;
                 rootnode.ImageIndex = 3;
                 rootnode.SelectedImageIndex = 3;
                 treeView1.Nodes.Add(rootnode);
                 TreenView_ClidNode(rootnode, parentid);
             }
        }

        /// <summary>
        /// 添加子节点
      /// </summary>
        /// <param name="node">根节点</param>
        /// <param name="id">根节点id</param>
        public void TreenView_ClidNode(TreeNode node, string id)
        {
            DataRow[] dr = dt.Select("sysparentid = '" + id + "'");
            for (int i = 0; i < dr.Length; i++)
            {
                string parentid = dr[i]["sysid"].ToString();
                string nodename = dr[i]["sysname"].ToString();
                TreeNode clidnode = new TreeNode();
                clidnode.Text = nodename;
                clidnode.SelectedImageIndex = 1;
                clidnode.ImageIndex = 1;
                node.Nodes.Add(clidnode);
                TreenView_ClidNode(clidnode, parentid);
                if (clidnode.Nodes.Count == 0)
                {
                    clidnode.ImageIndex = 0;
                    clidnode.SelectedImageIndex = 0;
                }
            }
        }

        /// <summary>
        /// 展开节点触发的事件
       /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void treeView1_AfterExpand(object sender, TreeViewEventArgs e)
        {
            TreeView tv = treeView1;
            TreeNode tn = e.Node;  //获取点击加号时所对应的节点
            if (tn.Level == 0)
            {
                this.treeView1.TopNode.ImageIndex = 3;
                this.treeView1.TopNode.SelectedImageIndex = 3;
            }
            else if (tn.Nodes.Count == 0)
            {
                tn.ImageIndex = 0;
                tn.SelectedImageIndex = 0;
            }
            else
            {
                tn.ImageIndex = 2;
                tn.SelectedImageIndex = 2;
            }
        }


        /// <summary>
        /// 闭合节点所触发的事件
       /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void treeView1_AfterCollapse(object sender, TreeViewEventArgs e)
        {
            TreeView tv = treeView1;
            TreeNode tn = e.Node;
            if (tn.Level == 0)
            {
                this.treeView1.TopNode.ImageIndex = 3;
                this.treeView1.TopNode.SelectedImageIndex = 3;
            }
            else if (tv.SelectedNode.Nodes.Count == 0)
            {
                tn.ImageIndex = 0;
                tn.SelectedImageIndex = 0;
            }
            else
            {
                tn.ImageIndex = 1;
                tn.SelectedImageIndex = 1;
            }
        }
    }
}