Add a Node Dynamically

ComponentOne TreeView for ASP.NET: TreeView for ASP.NET AJAX Task-Based Help > Adding, Inserting, and Removing Nodes Dynamically > Add a Node Dynamically

To dynamically add a node, complete the following:

1. Add a PlaceHolder control to the Web page.

2. Add a LinkButton server control using declarative syntax:

The OnClick attribute is included in the markup so when you click on the LinkButton control, the event will call the ClickAddNode event handler which we will later create.

3. Add the directive for the namespace to your source code.

• Visual Basic

Imports C1.Web.UI.Controls.C1TreeView

• C#

using C1.Web.UI.Controls.C1TreeView

4. Use the following code to create the dynamic treeview:

• Visual Basic

Private treeView As C1.Web.UI.Controls.C1TreeView.C1TreeView

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)

'create an instance of the class

treeView = New C1.Web.UI.Controls.C1TreeView.C1TreeView()

treeView.ID = "TreeView"

PlaceHolder1.Controls.Add(treeView)

If Not Page.IsPostBack Then

Dim P As New C1TreeViewNode()

P.Text = "Products"

P.Value = "PS"

P.Expanded = True

treeView.Nodes.Add(P)

Dim Pr1 As New C1TreeViewNode()

Pr1.Text = "Products 1"

Pr1.Value = "Pr1"

Pr1.Expanded = True

P.Nodes.Add(Pr1)

Dim Oview1 As New C1TreeViewNode()

Oview1.Text = "Overview"

Oview1.Value = "Oview1"

Pr1.Nodes.Add(Oview1)

Dim Down1 As New C1TreeViewNode()

Down1.Text = "Downloads"

Down1.Value = "Down1"

Pr1.Nodes.Add(Down1)

Dim Supp1 As New C1TreeViewNode()

Supp1.Text = "Support"

Supp1.Value = "Supp1"

Pr1.Nodes.Add(Supp1)

Dim Pr2 As New C1TreeViewNode()

Pr2.Text = "Products 2"

Pr2.Value = "Pr2"

Pr2.Expanded = True

P.Nodes.Add(Pr2)

Dim Oview2 As New C1TreeViewNode()

Oview2.Text = "Overview"

Oview2.Value = "Oview2"

Pr2.Nodes.Add(Oview2)

Dim Down2 As New C1TreeViewNode()

Down2.Text = "Downloads"

Down2.Value = "Down2"

Pr2.Nodes.Add(Down2)

Dim Supp2 As New C1TreeViewNode()

Supp2.Text = "Support"

Supp2.Value = "Supp2"

Pr2.Nodes.Add(Supp2)

End If

End Sub

• C#

private C1.Web.UI.Controls.C1TreeView.C1TreeView treeView;

protected void Page_Load(object sender, EventArgs e)

{

//create an instance of the class

treeView = new C1.Web.UI.Controls.C1TreeView.C1TreeView();

treeView.ID = "TreeView";

PlaceHolder1.Controls.Add(treeView);

if (!Page.IsPostBack) {

C1TreeViewNode P = new C1TreeViewNode();

P.Text = "Products";

P.Value = "PS";

P.Expanded = true;

treeView.Nodes.Add(P);

C1TreeViewNode Pr1 = new C1TreeViewNode();

Pr1.Text = "Products 1";

Pr1.Value = "Pr1";

Pr1.Expanded = true;

P.Nodes.Add(Pr1);

C1TreeViewNode Oview1 = new C1TreeViewNode();

Oview1.Text = "Overview";

Oview1.Value = "Oview1";

Pr1.Nodes.Add(Oview1);

C1TreeViewNode Down1 = new C1TreeViewNode();

Down1.Text = "Downloads";

Down1.Value = "Down1";

Pr1.Nodes.Add(Down1);

C1TreeViewNode Supp1 = new C1TreeViewNode();

Supp1.Text = "Support";

Supp1.Value = "Supp1";

Pr1.Nodes.Add(Supp1);

C1TreeViewNode Pr2 = new C1TreeViewNode();

Pr2.Text = "Products 2";

Pr2.Value = "Pr2";

Pr2.Expanded = true;

P.Nodes.Add(Pr2);

C1TreeViewNode Oview2 = new C1TreeViewNode();

Oview2.Text = "Overview";

Oview2.Value = "Oview2";

Pr2.Nodes.Add(Oview2);

C1TreeViewNode Down2 = new C1TreeViewNode();

Down2.Text = "Downloads";

Down2.Value = "Down2";

Pr2.Nodes.Add(Down2);

C1TreeViewNode Supp2 = new C1TreeViewNode();

Supp2.Text = "Support";

Supp2.Value = "Supp2";

Pr2.Nodes.Add(Supp2);

}

5. Create a ClickAddNode event handler to raise an event when you click the Add Node link button. This event will call the CreateNode method to add a new C1TreeViewNode.

• Visual Basic

Protected Sub ClickAddNode(ByVal sender As Object, ByVal e As EventArgs)

treeView.Nodes.Add(CreateNode())

End Sub

• C#

protected void ClickAddNode(object sender, EventArgs e)

{

treeView.Nodes.Add(CreateNode());

}

6. Use the CreateNode() function to dynamically add a new C1TreeViewNode when the LinkButton is clicked.

• Visual Basic

Private Function CreateNode() As C1TreeViewNode

Dim node As New C1TreeViewNode()

node.Text = "New Node"

node.Value = "NewNode"

Return node

End Function

• C#

private C1TreeViewNode CreateNode()

{

C1TreeViewNode node = new C1TreeViewNode();

node.Text = "New Node";

node.Value = "NewNode";

return node;

}

7. Run your project and click on the Add new Node link button to add a node.