<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="WebApplication3._Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>TreeView PopulateNodesFromClient Example</title>
<script type="text/javascript">
function SelectCheckBox()
{ var o = window.event.srcElement;
var inputobj ;
if (o.tagName == "INPUT" && o.type == "checkbox")
{
var parentobj = o.parentNode ;
inputobj = o ;
while(parentobj.tagName != "TABLE")
{ parentobj = parentobj.parentNode
}
var nextobj = parentobj.nextSibling
if (nextobj.tagName != "DIV")
return ;
var x = nextobj.getElementsByTagName("INPUT"); var s = "" ;
for ( var i = 0 ; i < x.length;i ++ )
{ if (x[i].tagName == "INPUT" && x[i].type == "checkbox")
{ if(inputobj.checked)
x[i].checked = true
else
x[i].checked = false
}
}
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>
<asp:Button ID="Button1" runat="server" Height="30px" onclick="Button1_Click"
Text="Button" />
TreeView PopulateNodesFromClient Example</h3>
<asp:TreeView ID="LinksTreeView"
Font-Names= "Arial"
ForeColor="Blue"
EnableClientScript="true"
PopulateNodesFromClient="true"
OnTreeNodePopulate="PopulateNode"
runat="server" ExpandDepth="1">
<Nodes>
<asp:TreeNode Text="Inventory"
SelectAction="None"
PopulateOnDemand="true"/>
</Nodes>
</asp:TreeView>
<br /><br />
<asp:Label id="Message" runat="server"/>
</form>
</body>
</html>
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Data.SqlClient;
namespace WebApplication3
{ public partial class _Default : System.Web.UI.Page
{
protected void Button1_Click(object sender, EventArgs e)
{ this.Button1.Text = this.LinksTreeView.Nodes[0].ChildNodes[0].ChildNodes[0].Text + " " +
this.LinksTreeView.Nodes[0].ChildNodes[0].ChildNodes[0].Checked.ToString();
}
protected void PopulateNode(Object sender, TreeNodeEventArgs e)
{ // Call the appropriate method to populate a node at a particular level.
switch (e.Node.Depth)
{ case 0:
// Populate the first-level nodes.
PopulateCategories(e.Node);
break;
case 1:
// Populate the second-level nodes.
PopulateProducts(e.Node);
break;
default:
// Do nothing.
break;
}
}
void PopulateCategories(TreeNode node)
{
// Query for the product categories. These are the values
// for the second-level nodes.
DataSet ResultSet = RunQuery("Select CategoryID, CategoryName From Categories");
// Create the second-level nodes.
if (ResultSet.Tables.Count > 0)
{
// Iterate through and create a new node for each row in the query results.
// Notice that the query results are stored in the table of the DataSet.
foreach (DataRow row in ResultSet.Tables[0].Rows)
{
// Create the new node. Notice that the CategoryId is stored in the Value property
// of the node. This will make querying for items in a specific category easier when
// the third-level nodes are created.
TreeNode newNode = new TreeNode();
newNode.Text = row["CategoryName"].ToString();
newNode.Value = row["CategoryID"].ToString();
// Set the PopulateOnDemand property to true so that the child nodes can be
// dynamically populated.
// ShowCheckBox 必须放在PopulateOnDemand 前面，否则复选框无法出现在树中。
newNode.ShowCheckBox = true;
if (node.Checked)
newNode.Checked = true;
newNode.PopulateOnDemand = true;
// Set additional properties for the node.
newNode.SelectAction = TreeNodeSelectAction.None;
// Add the new node to the ChildNodes collection of the parent node.
node.ChildNodes.Add(newNode);
}
}
}
void PopulateProducts(TreeNode node)
{
// Query for the products of the current category. These are the values
// for the third-level nodes.
DataSet ResultSet = RunQuery("Select ProductName From Products Where CategoryID=" + node.Value);
// Create the third-level nodes.
if (ResultSet.Tables.Count > 0)
{
// Iterate through and create a new node for each row in the query results.
// Notice that the query results are stored in the table of the DataSet.
foreach (DataRow row in ResultSet.Tables[0].Rows)
{
// Create the new node.
TreeNode NewNode = new TreeNode(row["ProductName"].ToString());
// Set the PopulateOnDemand property to false, because these are leaf nodes and
// do not need to be populated.
NewNode.ShowCheckBox = true;
if (node.Checked)
NewNode.Checked = true;
NewNode.PopulateOnDemand = false;
// Set additional properties for the node.
NewNode.SelectAction = TreeNodeSelectAction.None;
// Add the new node to the ChildNodes collection of the parent node.
node.ChildNodes.Add(NewNode);
}
}
}
DataSet RunQuery(String QueryString)
{
// Declare the connection string. This example uses Microsoft SQL Server
// and connects to the Northwind sample database.
String ConnectionString = "server=localhost;database=NorthWind;Integrated Security=SSPI";
SqlConnection DBConnection = new SqlConnection(ConnectionString);
SqlDataAdapter DBAdapter;
DataSet ResultsDataSet = new DataSet();
try
{
// Run the query and create a DataSet.
DBAdapter = new SqlDataAdapter(QueryString, DBConnection);
DBAdapter.Fill(ResultsDataSet);
// Close the database connection.
DBConnection.Close();
}
catch (Exception ex)
{
// Close the database connection if it is still open.
if (DBConnection.State == ConnectionState.Open)
{ DBConnection.Close();
}
Message.Text = "Unable to connect to the database.";
}
return ResultsDataSet;
}
protected void LinksTreeView_SelectedNodeChanged(object sender, EventArgs e)
{
}
protected void Page_Load(object sender, EventArgs e)
{ this.LinksTreeView.Attributes.Add("onclick", "SelectCheckBox()"); }
}
}