How to: Manage The Visibility of Check Boxes

• Dec 17, 2020
• 2 minutes to read

This example demonstrates how you can use the AllowCheckNodes and AllowCheck properties to manage the visibility of check boxes.

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 />
                    </Nodes>
                </dx:TreeViewNode>
                <dx:TreeViewNode />
            </Nodes>
        </dx:TreeViewNode>
        <dx:TreeViewNode>
            <Nodes>
                <dx:TreeViewNode />
                <dx:TreeViewNode />
                <dx:TreeViewNode />
                <dx:TreeViewNode />
            </Nodes>
        </dx:TreeViewNode>
    </Nodes>
</dx:ASPxTreeView>

<dx:ASPxButton ID="ASPxButton1" runat="server" OnClick="ASPxButton1_Click" Text="Disable checked nodes" />
<dx:ASPxButton ID="ASPxButton2" runat="server" OnClick="ASPxButton2_Click" Text="Enable checked nodes" />

Default.aspx.cs

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; });
}