TreeNodeEventArgs 클래스
정의
중요
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TreeNodeCheckChanged 컨트롤의 TreeNodeCollapsed, TreeNodeDataBound, TreeNodeExpanded, TreeNodePopulate 및 TreeView 이벤트에 대한 데이터를 제공합니다. 이 클래스는 상속될 수 없습니다.
public ref class TreeNodeEventArgs sealed : EventArgs
public sealed class TreeNodeEventArgs : EventArgs
type TreeNodeEventArgs = class
inherit EventArgs
Public NotInheritable Class TreeNodeEventArgs
Inherits EventArgs
- 상속
예제
다음 코드 예제에는 동적으로 사용 하 여 노드를 채우는 방법을 보여 줍니다는 TreeNodeEventArgs 이벤트 처리 메서드에 전달 되는 개체입니다.
<%@ Page Language="C#" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
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.
newNode.PopulateOnDemand = true;
// Set additional properties for the node.
newNode.SelectAction = TreeNodeSelectAction.Expand;
// 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.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;
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>TreeView PopulateNodesFromClient Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>TreeView PopulateNodesFromClient Example</h3>
<asp:TreeView id="LinksTreeView"
Font-Names= "Arial"
ForeColor="Blue"
EnableClientScript="true"
PopulateNodesFromClient="true"
OnTreeNodePopulate="PopulateNode"
runat="server">
<Nodes>
<asp:TreeNode Text="Inventory"
SelectAction="Expand"
PopulateOnDemand="true"/>
</Nodes>
</asp:TreeView>
<br /><br />
<asp:Label id="Message" runat="server"/>
</form>
</body>
</html>
<%@ Page Language="VB" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Sub PopulateNode(ByVal sender As Object, ByVal e As TreeNodeEventArgs)
' Call the appropriate method to populate a node at a particular level.
Select Case e.Node.Depth
Case 0
' Populate the first-level nodes.
PopulateCategories(e.Node)
Case 1
' Populate the second-level nodes.
PopulateProducts(e.Node)
Case Else
' Do nothing.
End Select
End Sub
Sub PopulateCategories(ByVal node As TreeNode)
' Query for the product categories. These are the values
' for the second-level nodes.
Dim ResultSet As DataSet = RunQuery("Select CategoryID, CategoryName From Categories")
' Create the second-level nodes.
If ResultSet.Tables.Count > 0 Then
' 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.
Dim row As DataRow
For Each 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.
Dim newNode As TreeNode = 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.
newNode.PopulateOnDemand = True
' Set additional properties for the node.
newNode.SelectAction = TreeNodeSelectAction.Expand
' Add the new node to the ChildNodes collection of the parent node.
node.ChildNodes.Add(newNode)
Next
End If
End Sub
Sub PopulateProducts(ByVal node As TreeNode)
' Query for the products of the current category. These are the values
' for the third-level nodes.
Dim ResultSet As DataSet = RunQuery("Select ProductName From Products Where CategoryID=" & node.Value)
' Create the third-level nodes.
If ResultSet.Tables.Count > 0 Then
' 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.
Dim row As DataRow
For Each row In ResultSet.Tables(0).Rows
' Create the new node.
Dim NewNode As TreeNode = New TreeNode(row("ProductName").ToString())
' Set the PopulateOnDemand property to false, because these are leaf nodes and
' do not need to be populated.
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)
Next
End If
End Sub
Function RunQuery(ByVal QueryString As String) As DataSet
' Declare the connection string. This example uses Microsoft SQL Server
' and connects to the Northwind sample database.
Dim ConnectionString As String = "server=localhost;database=NorthWind;Integrated Security=SSPI"
Dim DBConnection As SqlConnection = New SqlConnection(ConnectionString)
Dim DBAdapter As SqlDataAdapter
Dim ResultsDataSet As DataSet = 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 ex As Exception
' Close the database connection if it is still open.
If DBConnection.State = ConnectionState.Open Then
DBConnection.Close()
End If
Message.Text = "Unable to connect to the database."
End Try
Return ResultsDataSet
End Function
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>TreeView PopulateNodesFromClient Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>TreeView PopulateNodesFromClient Example</h3>
<asp:TreeView id="LinksTreeView"
Font-Names= "Arial"
ForeColor="Blue"
EnableClientScript="true"
PopulateNodesFromClient="true"
OnTreeNodePopulate="PopulateNode"
runat="server">
<Nodes>
<asp:TreeNode Text="Inventory"
SelectAction="Expand"
PopulateOnDemand="true"/>
</Nodes>
</asp:TreeView>
<br /><br />
<asp:Label id="Message" runat="server"/>
</form>
</body>
</html>
설명
TreeNodeEventArgs 클래스는 이벤트 처리 메서드에 전달 되는 이벤트 데이터를 저장 하는 데 사용 됩니다.
인스턴스의 초기 속성 값의 목록은 합니다 TreeNodeEventArgs 클래스를 참조 하십시오 TreeNodeEventArgs(TreeNode)합니다.
이벤트를 처리 하는 방법에 대 한 자세한 내용은 참조 하세요. 이벤트 처리 및 발생합니다.
생성자
TreeNodeEventArgs(TreeNode) |
지정된 TreeNode 개체를 사용하여 TreeNodeEventArgs 클래스의 새 인스턴스를 초기화합니다. |
속성
Node |
이벤트를 발생시킨 노드를 가져옵니다. |
메서드
Equals(Object) |
지정된 개체가 현재 개체와 같은지 확인합니다. (다음에서 상속됨 Object) |
GetHashCode() |
기본 해시 함수로 작동합니다. (다음에서 상속됨 Object) |
GetType() |
현재 인스턴스의 Type을 가져옵니다. (다음에서 상속됨 Object) |
MemberwiseClone() |
현재 Object의 단순 복사본을 만듭니다. (다음에서 상속됨 Object) |
ToString() |
현재 개체를 나타내는 문자열을 반환합니다. (다음에서 상속됨 Object) |
적용 대상
추가 정보
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