TreeViewNode.AllowCheck Property

Gets or sets a value to enable/disable the check box for a particular node.

Namespace: DevExpress.Web

Assembly: DevExpress.Web.v23.2.dll

NuGet Package: DevExpress.Web

Declaration

C#

[DefaultValue(true)]
public bool AllowCheck { get; set; }

VB.NET

<DefaultValue(True)>
Public Property AllowCheck As Boolean

Property Value

Type	Default	Description
Boolean	true	true if a check box is available; otherwise, false.

Remarks

The ASPxTreeView allows end-users to check nodes using node check boxes. The entire availability of node check boxes is controlled by the ASPxTreeView.AllowCheckNodes property. For individual nodes, the visibility of their check boxes can be specified using the AllowCheck property on the node level. A particular node’s check box is enabled if both the control’s ASPxTreeView.AllowCheckNodes and the node’s AllowCheck properties are set to true.

Note that the AllowCheck property doesn’t change a node’s checked state. It only hides/shows a check box. The checked state of an individual node can be specified using the node’s TreeViewNode.Checked property.

For more information, see the Check Box Support topic.

Example

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; });
}