掌握TreeView用法
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<ItemsNode> GetEveryOneByParent(int id)
13 {
14 DataTable dt=sqlHelper.GetDatatable("select * from ItemsNode where parentId =@id",
15 new SqlParameter("id",id));
16 List<ItemsNode> list = new List<ItemsNode>();
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<ItemsNode> 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<ItemsNode> 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<ItemsNode> 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<ItemsNode> 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 }
