1,、概述該篇文章開發(fā)使用的語言c#,，環(huán)境visualstudio2010,sql數(shù)據(jù)庫.主要內容包括： （1）treeView控件添加根節(jié)點,、子節(jié)點的基本方法,，節(jié)點的刪除。 （2）把treeView控件的節(jié)點數(shù)據(jù)保存到SQL數(shù)據(jù)包括中,，把數(shù)據(jù)庫數(shù)據(jù)表中的數(shù)據(jù)動態(tài)加載到treeView控件中,，控件節(jié)點的遞歸刪除（指的是遞歸刪除數(shù)據(jù)表的數(shù)據(jù)） 2、TreeView控件的基本用法為了演示相關方法、屬性的用法,，通過vs2010創(chuàng)建一個winform項目,，在項目中添加一個窗體，其布局如圖2-1所示
圖2-1 其中TreeView控件的名稱為：treeview1,文本框的名稱為：txtNodeName,，“添加根節(jié)點”按鈕的名稱為：btnAddRootNode,，“添加子節(jié)點”按鈕的名稱為：btnAddSonNode，“刪除選中節(jié)點”按鈕的名稱：btnDelete 添加節(jié)點,、刪除節(jié)點的代碼如下所示： 2.1添加根節(jié)點
1 private void btnAddRootNode_Click(object sender, EventArgs e)
2 {
3 //要添加的節(jié)點名稱為空,，即文本框是否為空
4 if(string.IsNullOrEmpty(txtNodeName.Text.Trim()))
5 {
6 MessageBox.Show("要添加的節(jié)點名稱不能為空！");
7 return;
8 }
9 //添加根節(jié)點
10 treeView1.Nodes.Add(txtNodeName.Text.Trim());
11 txtNodeName.Text = "";
12 }
2.2添加子節(jié)點
1 private void btnAddSonNode_Click(object sender, EventArgs e)
2 {
3 //要添加的節(jié)點名稱為空,，即文本框是否為空
4 if (string.IsNullOrEmpty(txtNodeName.Text.Trim()))
5 {
6 MessageBox.Show("要添加的節(jié)點名稱不能為空,！");
7 return;
8 }
9 if(treeView1.SelectedNode==null)
10 {
11 MessageBox.Show("請選擇要添加子節(jié)點的節(jié)點！");
12 return;
13 } treeView1.SelectedNode.Nodes.Add(txtNodeName.Text.Trim());
14 txtNodeName.Text = "";
15 }
2.3刪除選中節(jié)點
1 private void btnDelete_Click(object sender, EventArgs e)
2 {
3 if (treeView1.SelectedNode == null)
4 {
5 MessageBox.Show("請選擇要刪除的節(jié)點,！");
6 return;
7 }
8 treeView1.SelectedNode.Remove();
9 }
3,、TreeView控件在樹形菜單中的應用Treeview在產(chǎn)品類別管理、部門管理等樹狀多級菜單中的應用,，主要包括把樹控件中的數(shù)據(jù)保存到SQL數(shù)據(jù)表中,，把數(shù)據(jù)表中的數(shù)據(jù)動態(tài)加載到treeview控件中，以及刪除控件節(jié)點及數(shù)據(jù)表中的數(shù)據(jù),。 3.1數(shù)據(jù)表
create table TreeTest ( id int identity(1,1) primary key not null,//節(jié)點id nodeName nvarchar(50) not null,//節(jié)點名稱 parentId int not null//節(jié)點父id ) 3.2把節(jié)點數(shù)據(jù)存儲到數(shù)據(jù)表把treeView添加的節(jié)點信息存儲到數(shù)據(jù)表,，包括根節(jié)點、子節(jié)點,，所用的窗體界面如圖2-1所示,，控件的名稱保持不變，只是執(zhí)行代碼變了,。
1 private void btnAddRootNode_Click (object sender, EventArgs e)
2 {
3 if(string.IsNullOrEmpty(txtNodeName.Text.Trim()))
4 {
5 MessageBox.Show("請?zhí)顚懸砑拥墓?jié)點名稱,！");
6 return;
7 }
8 string sql = "insert into TreeTest(nodeName,parentId) output inserted.id values"+"("+" "+"'"+ txtNodeName.Text.Trim()+"'"+","+"'"+0+"'"+")";
9 int id = (int)sqlHelper.ExecuteScalar(sql);
10 TreeNode node1 = new TreeNode();
11 node1.Tag = id;//把自己的id存放在該節(jié)點tag對象里
12 node1.Text = txtNodeName.Text.Trim();
13 treeView1.Nodes.Add(node1);
14 txtNodeName.Text = "";
15 }
1 private void btnAddSonNode_Click (object sender, EventArgs e)
2 {
3 int id;
4 if(string.IsNullOrEmpty(txtNodeName.Text.Trim()))
5 {
6 return;
7 }
8 if(treeView1.SelectedNode==null)
9 {
10 MessageBox.Show("請選擇父節(jié)點");
11 return;
12 }
13 id =(int)treeView1.SelectedNode.Tag;//獲取父id
14 string sql = "insert into TreeTest(nodeName,parentId) output inserted.id values"+"(" + " " + "'" + txtNodeName.Text.Trim() + "'" + "," + "'" + id + "'" + ")";
15 int id1 = (int)sqlHelper.ExecuteScalar(sql);
16 TreeNode node1 = new TreeNode();
17 node1.Tag = id1;
18 node1.Text = txtNodeName.Text.Trim();
19 treeView1.SelectedNode.Nodes.Add(node1);
20 txtNodeName.Text = "";
21 }
3.3動態(tài)加載數(shù)據(jù)把數(shù)據(jù)表中的數(shù)據(jù)動態(tài)加載到treeView控件中，在treeView所在窗體的load事件中加載,，相應的代碼如下所示
1 private void Form3_Load(object sender, EventArgs e)
2 {
3 //加載數(shù)據(jù),，把數(shù)據(jù)加載到控件treeview1中
4 setTreeView(treeView1, 0);
5 }
6
7 //調用的時候parentId以0值開始 setTreeView(treeView1, 0);
8 private void setTreeView(TreeView tr1,int parentId)
9 {
10 string sql = "select * from TreeTest where parentId=" + parentId;
11 DataTable ds= sqlHelper.ExecuteDataTable(sql);
12 if (ds.Rows.Count > 0)
13 {
14 int pId = -1;
15 foreach (DataRow row in ds.Rows)
16 {
17 TreeNode node = new TreeNode();
18 node.Text = row["nodeName"].ToString();
19 node.Tag = (int)row["id"];
20 pId = (int)row["parentId"];
21 if (pId == 0)
22 {
23 //添加根節(jié)點
24 tr1.Nodes.Add(node);
25 }
26 else
27 {
28 //添加根節(jié)點之外的其他節(jié)點
29 RefreshChildNode(tr1,node,pId);
30 }
31 //查找以node為父節(jié)點的子節(jié)點
32 setTreeView(tr1,(int)node.Tag);
33
34 }
35 }
36
37 }
38 //處理根節(jié)點的子節(jié)點
39 private void RefreshChildNode(TreeView tr1,TreeNode treeNode, int parentId)
40 {
41 foreach (TreeNode node in tr1.Nodes)
42 {
43 if((int)node.Tag==parentId)
44 {
45 node.Nodes.Add(treeNode);
46 return;
47 }else if (node.Nodes.Count > 0)
48 {
49 FindChildNode(node, treeNode, parentId);
50 }
51 }
52 }
53
54 //處理根節(jié)點的子節(jié)點的子節(jié)點
55 private void FindChildNode(TreeNode tNode,TreeNode treeNode, int parentId)
56 {
57 foreach (TreeNode node in tNode.Nodes)
58 {
59 if ((int)node.Tag == parentId)
60 {
61 node.Nodes.Add(treeNode);
62 return;
63 }else if (node.Nodes.Count > 0)
64 {
65 FindChildNode(node,treeNode,parentId);
66 }
67
68 }
69
70 }
3.4、遞歸刪除節(jié)點,，這里指的是遞歸刪除節(jié)點在數(shù)據(jù)表中的信息
1 private void btnDelete_Click(object sender, EventArgs e)
2 {
3 if(treeView1.SelectedNode==null)
4 {
5 MessageBox.Show("請選擇要刪除的節(jié)點,！");
6 return;
7 }
8 //選中節(jié)點的id，也是其子節(jié)點的parentId
9 int id = (int)treeView1.SelectedNode.Tag;
10 nodeDelete(id);//遞歸刪除數(shù)據(jù)表中的數(shù)據(jù)
11 treeView1.SelectedNode.Remove();//刪除控件中的節(jié)點
12
13 }
14 //數(shù)據(jù)表中的數(shù)據(jù)的遞歸刪除方法
15 public void nodeDelete(int id)
16 {
17 string sql = "select * from TreeTest where parentId="+id;
18 DataTable ds = sqlHelper.ExecuteDataTable(sql);
19 if (ds.Rows.Count > 0)
20 {
21 //有子節(jié)點
22 foreach(DataRow row in ds.Rows)
23 {
24 //先刪除父節(jié)點
25 string delete = "delete from TreeTest where id=" + id;
26 int k = sqlHelper.ExecuteNonQuery(delete);
27 //查找子節(jié)點,，刪除
28 int id1 = (int)row["id"];
29 nodeDelete(id1);
30 }
31 }
32 else
33 {
34 //沒有子節(jié)點
35 string delete = "delete from TreeTest where id="+id;
36 int k = sqlHelper.ExecuteNonQuery(delete);
37 }
38 }
4,、TreeView控件的右鍵操作TreeView控件的右鍵操作，需要兩個winform窗體form3（圖4-1）,，form4（圖4-2）,，其中form3中放置treeview1控件，兩個contextMenuStrip，contextMenuStrip1和contextMenuStrip2,， form4用于彈出菜單 填寫要添加節(jié)點名稱
圖4-1
圖4-2
contextMenuStrip1
contextMenuStrip2 4.1 Form4窗體的代碼如下：
1 public partial class Form4 : Form
2 {
3 public string nodeName
4 {
5 get { return textBox1.Text.Trim(); }
6 }
7 public Form4()
8 {
9 InitializeComponent();
10 }
11
12 private void btnCancel_Click(object sender, EventArgs e)
13 {
14 DialogResult = DialogResult.Cancel;
15 }
16
17 private void btnConfirm_Click(object sender, EventArgs e)
18 {
19 if(string.IsNullOrEmpty(textBox1.Text.Trim()))
20 {
21 MessageBox.Show("請?zhí)顚懝?jié)點名稱,！");
22 return;
23 }
24 DialogResult = DialogResult.OK;
25 }
26 }
4.2 form3窗體的代碼如下：
1 public partial class Form3 : Form
2 {
3 public Form3()
4 {
5 InitializeComponent();
6 }
7 private void treeView1_MouseDown(object sender, MouseEventArgs e)
8 {
9 if(e.Button==MouseButtons.Right)
10 {
11 Point ClickPoint = new Point(e.X, e.Y);
12 int x = e.X;
13 int y = e.Y;
14 TreeNode CurrentNode = treeView1.GetNodeAt(ClickPoint);
15 if (CurrentNode is TreeNode)//判斷你點的是不是一個節(jié)點
16 {
17 treeView1.SelectedNode = CurrentNode;
18 CurrentNode.ContextMenuStrip = this.contextMenuStrip1;
19 contextMenuStrip1.Show(MousePosition);
20 }
21 else
22 {
23 treeView1.ContextMenuStrip = this.contextMenuStrip2;
24 contextMenuStrip2.Show(MousePosition);
25 }
26 }
27 }
28
29 private void 添加子節(jié)點ToolStripMenuItem_Click(object sender, EventArgs e)
30 {
31 Form4 f5 = new Form4();
32 if (f5.ShowDialog() == DialogResult.OK)
33 {
34 treeView1.SelectedNode.Nodes.Add(f5.nodeName);
35 }
36 }
37
38 private void 刪除選中節(jié)點ToolStripMenuItem_Click(object sender, EventArgs e)
39 {
40 treeView1.SelectedNode.Remove();
41 }
42
43 private void 添加根節(jié)點ToolStripMenuItem1_Click(object sender, EventArgs e)
44 {
45 Form4 f4 = new Form4();
46 if (f4.ShowDialog() == DialogResult.OK)
47 {
48 treeView1.Nodes.Add(f4.nodeName);
49 }
50 }
51
52 private void 清空ToolStripMenuItem1_Click(object sender, EventArgs e)
53 {
54 treeView1.Nodes.Clear();
55 }
56 }
4.3、示例中用到的sqlHelper.cs文件代碼如下所示
1 using System;
2 using System.Collections.Generic;
3 using System.Linq;
4 using System.Text;
5 using System.Data;
6 using System.Data.SqlClient;
7 using System.Windows.Forms;
8
9 namespace CRMProject.DAL
10 {
11 class SqlHelper
12 {
13 static DataTable dtInfo = new DataTable();
14 public static SqlConnection My_con; //定義一個sqlConnection類型的公共變量My_con,，用于判斷數(shù)據(jù)庫是否連接成功
15
16
17 public static readonly string connstr =
18 ConfigurationManager.ConnectionStrings["dbconnstr"].ConnectionString;
19
20 public static int ExecuteNonQuery(string cmdText,
21 params SqlParameter[] parameters)
22 {
23 using (SqlConnection conn = new SqlConnection(connstr))
24 {
25 conn.Open();
26 using (SqlCommand cmd = conn.CreateCommand())
27 {
28 cmd.CommandText = cmdText;
29 cmd.CommandTimeout = 3000;
30 cmd.Parameters.AddRange(parameters);
31 return cmd.ExecuteNonQuery();
32 }
33 }
34 }
35
36 public static void dgrd_Connection(string strSql, DataGridView dgrd, int start, int pagesize, string tableName)
37 {
38
39 try
40 {
41 SqlDataAdapter adapter = new SqlDataAdapter(strSql, getcon());
42 DataSet dataSet = new DataSet();
43 adapter.Fill(dataSet, start, pagesize, tableName);
44 dtInfo = dataSet.Tables[tableName];
45 dgrd.DataSource = dataSet.Tables[tableName];
46 dgrd.AllowUserToAddRows = false;
47
48 }
49 catch { }
50 }
51
52 public static SqlConnection getcon()
53 {
54
55
56 My_con = new SqlConnection(connstr); //用SqlConnection對象與指定的數(shù)據(jù)庫相連接
57 My_con.Open(); //打開數(shù)據(jù)庫連接
58 return My_con; //返回SqlConnection對象的信息
59
60
61 }
62 public static int Count(string strSql)
63 {
64 using (SqlConnection conn = new SqlConnection(connstr))
65 {
66 conn.Open();
67 using (SqlCommand cmd = conn.CreateCommand())
68 {
69 try
70 {
71 cmd.CommandText = strSql;
72 cmd.CommandTimeout = 3000;
73 int n = int.Parse(cmd.ExecuteScalar().ToString());
74 return n;
75
76 }
77 catch { return 0; }
78 }
79 }
80 }
81 public static object ExecuteScalar(string cmdText,
82 params SqlParameter[] parameters)
83 {
84 using (SqlConnection conn = new SqlConnection(connstr))
85 {
86 conn.Open();
87 using (SqlCommand cmd = conn.CreateCommand())
88 {
89 cmd.CommandText = cmdText;
90 cmd.CommandTimeout = 3000;
91 cmd.Parameters.AddRange(parameters);
92 return cmd.ExecuteScalar();
93 }
94 }
95 }
96
97 public static DataTable ExecuteDataTable(string cmdText,
98 params SqlParameter[] parameters)
99 {
100 using (SqlConnection conn = new SqlConnection(connstr))
101 {
102 conn.Open();
103 using (SqlCommand cmd = conn.CreateCommand())
104 {
105 cmd.CommandText = cmdText;
106 cmd.CommandTimeout = 3000;
107 cmd.Parameters.AddRange(parameters);
108 using (SqlDataAdapter adapter = new SqlDataAdapter(cmd))
109 {
110 DataTable dt = new DataTable();
111 adapter.Fill(dt);
112 return dt;
113 }
114 }
115 }
116 }
117
118 public static SqlDataReader ExecuteDataReader(string cmdText,
119 params SqlParameter[] parameters)
120 {
121 SqlConnection conn = new SqlConnection(connstr);
122 conn.Open();
123 using (SqlCommand cmd = conn.CreateCommand())
124 {
125 cmd.CommandText = cmdText;
126 cmd.CommandTimeout = 3000;
127 cmd.Parameters.AddRange(parameters);
128 return cmd.ExecuteReader(CommandBehavior.CloseConnection);
129 }
130 }
131 }
132 }
5,、源碼下載地址鏈接：http://pan.baidu.com/s/1mi5DGi0 密碼：t22u
from：https://www.cnblogs.com/net064/p/5534697.html
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