How to: Manage The Visibility of Check Boxes

• Aug 01, 2019
• 2 minutes to read

This example demonstrates how you can use the ASPxTreeView's AllowCheckNodes and TreeViewNode's AllowCheck properties to manage the visibility of check boxes.See also:TreeView - How to manage the visibility of check boxes via the AllowCheck property

Note

A complete sample project is available at https://github.com/DevExpress-Examples/aspxtreeview-how-to-manage-the-visibility-of-check-boxes-via-the-allowcheck-property-e2500

Default.aspx

<dx:ASPxRadioButtonList ID="ASPxRadioButtonList1" runat="server" 
    AutoPostBack="True" ClientIDMode="AutoID" 
    onselectedindexchanged="ASPxRadioButtonList1_SelectedIndexChanged" 
    SelectedIndex="0">
    <Items>
        <dx:ListEditItem Text="Hide all check boxes" Value="HideAll" />
        <dx:ListEditItem Text="Show check boxes for leaf nodes only" Value="ShowLeaves" />
        <dx:ListEditItem Text="Show all check boxes" Value="Show" />
    </Items>
</dx:ASPxRadioButtonList>


<dx:ASPxTreeView ID="ASPxTreeView1" runat="server" ClientIDMode="AutoID">
    <Nodes>
        <dx:TreeViewNode>
            <Nodes>
                <dx:TreeViewNode>
                    <Nodes>
                        <dx:TreeViewNode>
                        </dx:TreeViewNode>
                        <dx:TreeViewNode>
                        </dx:TreeViewNode>
                    </Nodes>
                </dx:TreeViewNode>
                <dx:TreeViewNode>
                </dx:TreeViewNode>
            </Nodes>
        </dx:TreeViewNode>
        <dx:TreeViewNode>
            <Nodes>
                <dx:TreeViewNode>
                </dx:TreeViewNode>
                <dx:TreeViewNode>
                </dx:TreeViewNode>
                <dx:TreeViewNode>
                </dx:TreeViewNode>
                <dx:TreeViewNode>
                </dx:TreeViewNode>
            </Nodes>
        </dx:TreeViewNode>
    </Nodes>
</dx:ASPxTreeView>
         <br />
         <br />
         <dx:ASPxButton ID="ASPxButton1" runat="server" OnClick="ASPxButton1_Click" Text="Disable checked nodes">
         </dx:ASPxButton>
         <br />
         <dx:ASPxButton ID="ASPxButton2" runat="server" OnClick="ASPxButton2_Click" Text="Enable checked nodes">
         </dx:ASPxButton>

Default.aspx.cs

using DevExpress.Web.ASPxTreeView;
using DevExpress.Web.ASPxEditors;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e) {
        if (!IsPostBack) {
            ASPxTreeView1.AllowCheckNodes = !(ASPxRadioButtonList1.SelectedIndex == 0);
            ASPxTreeView1.ExpandAll();
        }
    }

    protected void ASPxRadioButtonList1_SelectedIndexChanged(object sender, EventArgs e) {
        ASPxRadioButtonList rblOptions = sender as ASPxRadioButtonList;
        switch (rblOptions.SelectedIndex) {
            case 0:
                ASPxTreeView1.AllowCheckNodes = false;
                break;
            case 1:
                ASPxTreeView1.AllowCheckNodes = true;
                PerformActionOnNodesRecursive(ASPxTreeView1.Nodes, delegate(TreeViewNode node) { node.AllowCheck = node.Nodes.Count == 0; });
                break;
            case 2:
                ASPxTreeView1.AllowCheckNodes = true;
                PerformActionOnNodesRecursive(ASPxTreeView1.Nodes, delegate(TreeViewNode node) { node.AllowCheck = true; });
                break;
        }
    }

    protected void PerformActionOnNodesRecursive(TreeViewNodeCollection nodes, Action<TreeViewNode> action) {
        foreach (TreeViewNode node in nodes) {
            action(node);
            if (node.Nodes.Count > 0)
                PerformActionOnNodesRecursive(node.Nodes, action);
        }
    }
    protected void ASPxButton1_Click(object sender, EventArgs e) {
        PerformActionOnNodesRecursive(ASPxTreeView1.Nodes, delegate(TreeViewNode node) { node.Enabled = !node.Checked;});
    }
    protected void ASPxButton2_Click(object sender, EventArgs e) {
        PerformActionOnNodesRecursive(ASPxTreeView1.Nodes, delegate(TreeViewNode node) { node.Enabled = true; });
    }
}