TreeView.ShowCheckBoxes Property
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Gets or sets a value indicating which node types will display a check box in the TreeView control.
public:
property System::Web::UI::WebControls::TreeNodeTypes ShowCheckBoxes { System::Web::UI::WebControls::TreeNodeTypes get(); void set(System::Web::UI::WebControls::TreeNodeTypes value); };public System.Web.UI.WebControls.TreeNodeTypes ShowCheckBoxes { get; set; }member this.ShowCheckBoxes : System.Web.UI.WebControls.TreeNodeTypes with get, setPublic Property ShowCheckBoxes As TreeNodeTypesProperty Value
A bitwise combination of the TreeNodeTypes values. The default is TreeNodeType.None.
Exceptions
The bitwise combination value is outside the range of the TreeNodeTypes enumeration.
Examples
The following code example demonstrates how to use the ShowCheckBoxes property to show and hide the check boxes for the different node types.
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void Button_Click(Object sender, EventArgs e)
{
if(LinksTreeView.CheckedNodes.Count > 0)
{
// Clear the message label.
Message.Text = "You selected: <br /><br />";
// Iterate through the CheckedNodes collection and display the selected nodes.
foreach (TreeNode node in LinksTreeView.CheckedNodes)
{
Message.Text += node.Text + "<br />";
}
}
else
{
Message.Text = "No items selected.";
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>TreeView ShowCheckBoxes Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>TreeView ShowCheckBoxes Example</h3>
<!-- Set the ShowCheckBoxes property declaratively. -->
<!-- Because the ShowCheckBoxes property uses a flag -->
<!-- enumeration, you can combine multiple values by -->
<!-- using the bitwise OR operator. In declarative -->
<!-- syntax, this is done using a comma separated -->
<!-- list. -->
<asp:TreeView id="LinksTreeView"
Font-Names= "Arial"
ForeColor="Blue"
ExpandDepth="2"
ShowCheckBoxes="Parent,Leaf"
runat="server">
<LevelStyles>
<asp:TreeNodeStyle ChildNodesPadding="10"
Font-Bold="true"
Font-Size="12pt"
ForeColor="DarkGreen"/>
<asp:TreeNodeStyle ChildNodesPadding="5"
Font-Bold="true"
Font-Size="10pt"/>
<asp:TreeNodeStyle ChildNodesPadding="5"
Font-UnderLine="true"
Font-Size="10pt"/>
<asp:TreeNodeStyle ChildNodesPadding="10"
Font-Size="8pt"/>
</LevelStyles>
<Nodes>
<asp:TreeNode Text="Table of Contents"
SelectAction="None">
<asp:TreeNode Text="Chapter One">
<asp:TreeNode Text="Section 1.0">
<asp:TreeNode Text="Topic 1.0.1"/>
<asp:TreeNode Text="Topic 1.0.2"/>
<asp:TreeNode Text="Topic 1.0.3"/>
</asp:TreeNode>
<asp:TreeNode Text="Section 1.1">
<asp:TreeNode Text="Topic 1.1.1"/>
<asp:TreeNode Text="Topic 1.1.2"/>
<asp:TreeNode Text="Topic 1.1.3"/>
<asp:TreeNode Text="Topic 1.1.4"/>
</asp:TreeNode>
</asp:TreeNode>
<asp:TreeNode Text="Chapter Two">
<asp:TreeNode Text="Section 2.0">
<asp:TreeNode Text="Topic 2.0.1"/>
<asp:TreeNode Text="Topic 2.0.2"/>
</asp:TreeNode>
</asp:TreeNode>
</asp:TreeNode>
<asp:TreeNode Text="Appendix A" />
<asp:TreeNode Text="Appendix B" />
<asp:TreeNode Text="Appendix C" />
</Nodes>
</asp:TreeView>
<br /><br />
<asp:Button id="Submit"
Text="Select Items"
OnClick="Button_Click"
runat="server"/>
<br /><br />
<asp:Label id="Message"
runat="server"/>
</form>
</body>
</html>
<%@ Page Language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Sub Button_Click(ByVal sender As Object, ByVal e As EventArgs)
If LinksTreeView.CheckedNodes.Count > 0 Then
' Clear the message label.
Message.Text = "You selected: <br /><br />"
' Iterate through the CheckedNodes collection and display the selected nodes.
Dim node As TreeNode
For Each node In LinksTreeView.CheckedNodes
Message.Text &= node.Text & "<br />"
Next
Else
Message.Text = "No items selected."
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>TreeView ShowCheckBoxes Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>TreeView ShowCheckBoxes Example</h3>
<!-- Set the ShowCheckBoxes property declaratively. -->
<!-- Because the ShowCheckBoxes property uses a flag -->
<!-- enumeration, you can combine multiple values by -->
<!-- using the bitwise OR operator. In declarative -->
<!-- syntax, this is done using a comma separated -->
<!-- list. -->
<asp:TreeView id="LinksTreeView"
Font-Names= "Arial"
ForeColor="Blue"
ExpandDepth="2"
ShowCheckBoxes="Parent,Leaf"
runat="server">
<LevelStyles>
<asp:TreeNodeStyle ChildNodesPadding="10"
Font-Bold="true"
Font-Size="12pt"
ForeColor="DarkGreen"/>
<asp:TreeNodeStyle ChildNodesPadding="5"
Font-Bold="true"
Font-Size="10pt"/>
<asp:TreeNodeStyle ChildNodesPadding="5"
Font-UnderLine="true"
Font-Size="10pt"/>
<asp:TreeNodeStyle ChildNodesPadding="10"
Font-Size="8pt"/>
</LevelStyles>
<Nodes>
<asp:TreeNode Text="Table of Contents"
SelectAction="None">
<asp:TreeNode Text="Chapter One">
<asp:TreeNode Text="Section 1.0">
<asp:TreeNode Text="Topic 1.0.1"/>
<asp:TreeNode Text="Topic 1.0.2"/>
<asp:TreeNode Text="Topic 1.0.3"/>
</asp:TreeNode>
<asp:TreeNode Text="Section 1.1">
<asp:TreeNode Text="Topic 1.1.1"/>
<asp:TreeNode Text="Topic 1.1.2"/>
<asp:TreeNode Text="Topic 1.1.3"/>
<asp:TreeNode Text="Topic 1.1.4"/>
</asp:TreeNode>
</asp:TreeNode>
<asp:TreeNode Text="Chapter Two">
<asp:TreeNode Text="Section 2.0">
<asp:TreeNode Text="Topic 2.0.1"/>
<asp:TreeNode Text="Topic 2.0.2"/>
</asp:TreeNode>
</asp:TreeNode>
</asp:TreeNode>
<asp:TreeNode Text="Appendix A" />
<asp:TreeNode Text="Appendix B" />
<asp:TreeNode Text="Appendix C" />
</Nodes>
</asp:TreeView>
<br /><br />
<asp:Button id="Submit"
Text="Select Items"
OnClick="Button_Click"
runat="server"/>
<br /><br />
<asp:Label id="Message"
runat="server"/>
</form>
</body>
</html>
Remarks
To provide multi-node selection support in the TreeView control, you can display check boxes next to the image for a node. Use the ShowCheckBoxes property to specify which node types will display a check box. For example, if this property is set to TreeNodeType.Parent, check boxes are displayed for each parent node in the tree. The following table lists the valid values for this property.
| Node type | Description |
|---|---|
TreeNodeType.All |
Check boxes are displayed for all nodes. |
TreeNodeType.Leaf |
Check boxes are displayed for all leaf nodes. |
TreeNodeType.None |
Check boxes are not displayed. |
TreeNodeType.Parent |
Check boxes are displayed for all parent nodes. |
TreeNodeType.Root |
Check boxes are displayed for all root nodes. |
The enumeration type that is used for the ShowCheckBoxes property is a flag enumeration, which allows you to combine values through bitwise operations. For example, to display check boxes for the parent and leaf nodes, use the bitwise OR operator to combine the TreeNodeType.Parent and TreeNodeType.Leaf values.
To determine which nodes have their check box selected, iterate through the nodes of the CheckedNodes collection.
Note
You can override the ShowCheckBoxes setting by setting the ShowCheckBox property for each node.
If you need to provide only single-selection support, consider using the SelectedNode property.
The value of this property is stored in view state.
