掌握TreeView用法-白红宇

掌握TreeView用法

阅读量：6220 次

发布时间：2019-06-21

本文共 9144 字，大约阅读时间需要 30 分钟。

DAL层代码：

1 using System.Collections.Generic;  2 using System.Data;  3 using DataTreeModel;  4 using System.Data.SqlClient;  5 using System.Windows.Forms;  6  7 namespace DataTreeDAL  8 {
    9     class TreesNodeDAL 10     {
   11         //根据Parentid返回表中所有的的实体对象 12         public IEnumerable
     
       GetEveryOneByParent(int id) 13         { 14         DataTable dt=sqlHelper.GetDatatable("select * from ItemsNode where parentId =@id", 15             new SqlParameter("id",id)); 16         List
      
        list = new List
       
        (); 17             foreach (DataRow row in dt.Rows) 18             {
   19                 list.Add(CreateItemsNose(row));//添加对象 20             } 21             return list; 22         } 23         //更新表中的记录 24         public int UpdateRecord(ItemsNode item) 25         {
   26          return sqlHelper.ExecuteNonQuery("update ItemsNode set name=@name,content=@content where id=@id", new SqlParameter("name", item.name), new SqlParameter("content", item.content),new 27              SqlParameter("id",item.Id)); 28         } 29 30         public int InsertRecord(ItemsNode item) 31         {
   32             return sqlHelper.ExecuteNonQuery("Insert into ItemsNode (name,content,parentId) values(@name,@content,@parentId)", new SqlParameter("name", item.name), new SqlParameter("content", item.content), new 33             SqlParameter("parentId", item.parentId)); 34         } 35 36         public void DeleteNode(int ParentId) 37         {
   38             //获得以该节点为父节点的所有子节点 39             IEnumerable
        
          childens = GetEveryOneByParent(ParentId); 40             foreach (ItemsNode child in childens) 41             {
   42                 DeleteNode((int)child.Id); 43             } 44            Delete(ParentId); 45         } 46       47         //实例化对象 48         private static ItemsNode CreateItemsNose(DataRow row) 49         {
   50             ItemsNode item = new ItemsNode(); 51             item.Id = row.IsNull("Id")?null:(int?)row["Id"]; 52             item.name = (string)row["name"]; 53             item.parentId = row.IsNull("parentId") ? null : (int?)row["parentId"]; 54             item.content = (string)row["content"]; 55             return item; 56         } 57         //删除操作 58         public  int Delete(int id) 59         {
   60             return sqlHelper.ExecuteNonQuery("delete from ItemsNode where id=@id", 61             new SqlParameter("id", id)); 62         } 63     } 64 }

BLL层代码：

1 using System;  2 using System.Collections.Generic;  3 using System.Text;  4 using DataTreeDAL;  5 using DataTreeModel;  6  7 namespace DataTreeBLL  8 {
    9     class TreeNodeBLL 10     {
   11         //获得所有对象 12         public IEnumerable
     
       GetEveryOneByParent(int id) 13         {
   14             return new TreesNodeDAL().GetEveryOneByParent(id); 15         } 16         //更新 17         public int UpdateRecord(ItemsNode item) 18         {
   19             return new TreesNodeDAL().UpdateRecord( item); 20         } 21 22         //增加 23         public int InsertRecord(ItemsNode item) 24         {
   25             return new TreesNodeDAL().InsertRecord(item); 26         } 27 28         public void DeleteAllNode(int ParentId) 29         {
   30             new TreesNodeDAL().DeleteNode(ParentId); 31         } 32     } 33 }

UI层代码：

1 using System;   2 using System.Collections.Generic;   3 using System.Windows.Forms;   4 using DataTreeBLL;   5 using DataTreeModel;   6   7 namespace DataTree   8 {
     9     public partial class Form1 : Form  10     {
    11         public Form1()  12         {
    13             InitializeComponent();  14         }  15  16         private void Form1_Load(object sender, EventArgs e)  17         {
    18             //获取所有的父节点对象  19           IEnumerable
     
       items= new TreeNodeBLL().GetEveryOneByParent(0);  20            21             foreach(ItemsNode item in items)  22             {   23                 //创建一个节点实例  24                 TreeNode Fnode = new TreeNode();  25                 Fnode.Text = item.name;  26                 Fnode.Tag = item;  27                 treeView1.Nodes.Add(Fnode);  28                 GetChildNode(Fnode,(int)item.Id);  29             }  30             treeView1.ExpandAll();  31         }  32         //遍历子节点  33         protected void GetChildNode(TreeNode Pnode,int id)  34         {
    35             //获取所有以此节点最为的父节点对象  36             IEnumerable
      
        items = new TreeNodeBLL().GetEveryOneByParent(id);  37             foreach (ItemsNode item in items)  38             {
    39                 TreeNode Fnode = new TreeNode();  40                 Fnode.Text = item.name;  41                 Fnode.Tag = item;//把节点的Tag指向对象  42                 Pnode.Nodes.Add(Fnode);  43                 GetChildNode(Fnode, (int)item.Id);  44             }  45         }  46  47         private void treeView1_AfterSelect(object sender, TreeViewEventArgs e)  48         {
    49             ItemsNode item = (ItemsNode)e.Node.Tag;  50             tb_content.Text = item.content;  51         }  52  53         private void bt_modify_Click(object sender, EventArgs e)  54         {
    55             ItemsNode item = (ItemsNode)treeView1.SelectedNode.Tag;  56             Frmodify form = new Frmodify();  57             form.FName = item.name;  58             form.Content = item.content;  59             if (form.ShowDialog()== DialogResult.OK)//递交修改指令  60             {
    61                 item.name = form.FName;  62                 item.content = form.Content;  63                 new TreeNodeBLL().UpdateRecord(item);  64                 treeView1.SelectedNode.Text = item.name;  65                 tb_content.Text = item.content;  66             }  67         }  68  69         private void bt_Insert_1_Click(object sender, EventArgs e)  70         {
    71             Frmodify form = new Frmodify();  72             if (form.ShowDialog() == DialogResult.OK)  73             {
    74                 ItemsNode item = new ItemsNode();  75                 item.name=form.FName;  76                 item.content=form.Content;  77                 item.parentId = 0;//一级节点  78                 new TreeNodeBLL().InsertRecord(item);  79                 TreeNode Node = new TreeNode();  80                 Node.Text=item.name;  81                 Node.Tag=item;  82                 treeView1.Nodes.Add(Node);  83             }  84         }  85  86         private void bt_Insert2_Click(object sender, EventArgs e)  87         {
    88             TreeNode CurrentNode = treeView1.SelectedNode;  89             Frmodify form = new Frmodify();  90             if (form.ShowDialog() == DialogResult.OK)  91             {
    92                 ItemsNode item = (ItemsNode)CurrentNode.Tag;  93                 item.name = form.FName;  94                 item.content = form.Content;  95                 item.parentId=item.Id;  96                 new TreeNodeBLL().InsertRecord(item);  97                 //显示到界面  98                 TreeNode Node = new TreeNode();  99                 Node.Text = item.name; 100                 Node.Tag = item; 101                 CurrentNode.Nodes.Add(Node); 102             } 103         } 104 105         private void bt_Delete_Click(object sender, EventArgs e) 106         {
   107             TreeNode Node = treeView1.SelectedNode; 108             Node.Remove(); 109             ItemsNode item = (ItemsNode)Node.Tag; 110             new TreeNodeBLL().DeleteAllNode((int)item.Id); 111         } 112     } 113 }

SQLhelper 类

1 using System.Data;  2 using System.Data.SqlClient;  3 using System.Configuration;  4  5 namespace DataTreeDAL  6 {
    7     class sqlHelper  8     {
    9         protected static readonly string conStr = ConfigurationManager.ConnectionStrings["conStr"].ConnectionString; 10         //返回一个结果集 11         public static DataTable GetDatatable(string sql,params SqlParameter[] Paramers) 12         {
   13             using (SqlConnection con = new SqlConnection(conStr))//创建一个连接 14             {
   15                 con.Open();//打开连接通道 16                 using (SqlCommand cmd =con.CreateCommand())//创建一个命令对象 17                 {
   18                     cmd.CommandText = sql; 19                     cmd.Parameters.AddRange(Paramers); 20                     SqlDataAdapter da = new SqlDataAdapter(cmd); 21                     DataTable dt = new DataTable(); 22                     da.Fill(dt); 23                     return dt; 24                 } 25             } 26         } 27        28         public static int ExecuteNonQuery(string sql, params SqlParameter[] Paramers) 29         {
   30             using (SqlConnection con = new SqlConnection(conStr))//创建一个连接 31             {
   32                 con.Open();//打开连接通道 33                 using (SqlCommand cmd = con.CreateCommand())//创建一个命令对象 34                 {
   35                     cmd.CommandText = sql; 36                     cmd.Parameters.AddRange(Paramers); 37                     return cmd.ExecuteNonQuery(); 38                 } 39             } 40         } 41     } 42 }