ASPxClientTreeList.GetNodeState(nodeKey) Method

Returns the specified node’s state.

Declaration

GetNodeState(
    nodeKey: string
): string

Parameters

Name	Type	Description
nodeKey	string	A String value that identifies the node.

Returns

Type	Description
string	A String value that represents the specified node’s state.

Remarks

The GetNodeState method returns the following values:

• NotFound - the specified node was not found;
• Collapsed - the specified node is collapsed;
• Expanded - the specified node is expanded;
• Child - the specified node has no child nodes.

Example

This example demonstrates how to use the GetFocusedNodeKey method to expand and collapse tree nodes based on the state of a node (collapsed or expanded). You can get the node state by calling the GetNodeState(nodeKey) method in the FocusedNodeChanged event.

Demo limitation: if you close the topmost parent node and do not have other nodes except that one, you will have to expand this node by clicking the Expand Button.

Default.aspx

<script>
    function OnFocusedNodeChange(s, e) {
        var nodeKey = s.GetFocusedNodeKey();
        var nodeState = s.GetNodeState(nodeKey);

        if (nodeState === "Collapsed")
            s.ExpandNode(nodeKey);
        else if (nodeState === "Expanded")
            s.CollapseNode(nodeKey);
    };
</script>
<dx:ASPxTreeList ID="TreeList"
    runat="server"
    AutoGenerateColumns="False" 
    DataSourceID="ProductsDataSource" 
    KeyFieldName="EmployeeID" 
    ParentFieldName="ReportsTo"
    Width="50%">
    <Columns>
        <dx:TreeListTextColumn FieldName="EmployeeID" VisibleIndex="0" ReadOnly="true"></dx:TreeListTextColumn>
        <dx:TreeListTextColumn FieldName="LastName" VisibleIndex="1"></dx:TreeListTextColumn>
        <dx:TreeListTextColumn FieldName="FirstName" VisibleIndex="2"></dx:TreeListTextColumn>
    </Columns>
    <SettingsBehavior AllowFocusedNode="true" FocusNodeOnLoad="false" />
    <ClientSideEvents FocusedNodeChanged="OnFocusedNodeChange" />
</dx:ASPxTreeList>
<br />

<asp:AccessDataSource ID="ProductsDataSource" runat="server"
    DataFile="~/App_Data/nwind.mdb"
    SelectCommand="SELECT [EmployeeID], [LastName], [FirstName], [ReportsTo] FROM [Employees]">
</asp:AccessDataSource>

Default.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page {
}