Creating a Treeview Menu in ASP.NET with C#

Introduction

Most Web sites/Web applications have menus to navigate the site, but either you have to use complex DHTML or a third-party tool to provide the menu. Instead, you can use the Treeview control shipped with Internet Explorer’s Web controls to solve this problem.

Background

Internet Explorer Web controls is shipped with controls that can be used to provide better site navigation to users visiting your site. This article looks at the Treeview control. Other controls, such as the Tab strip control, also ship with the IE Web Controls. I leave those for you to explore.

Using the Code

Download http://www.asp.net/IEWebControls/Download.aspx?tabindex=0&tabid=1. Install the downloaded file. Go to the IE Web Controls <install> directory and edit the Build.bat to add a path to csc.exe (by, default csc.exe is found in C:WINNTMicrosoft.NETFramework<framework version>). Execute Build.bat from the command prompt. A DLL file by the name of Microsoft.Web.UI.WebControls.dll is created in the <IE Web Controls>/build directory. Follow these steps:

1. Copy the DLL file to the bin directory of the new application’s folder or add a reference to it (VS.Net users).
2. Register the control using the Register tag <%@ Register TagPrefix="ie" Namespace="Microsoft.Web.UI.WebControls" Assembly="Microsoft.Web.UI.WebControls"%>.
3. Add the control using <ie:TreeView runat=”server” ID= “Treeview1”></ie:treeview>.
4. Inside the .cs file, use the namespace Microsoft.Web.UI.WebControls.
5. Use the following code to programatically add the values to the Treeview control.
6. Declare a variable as protected: Microsoft.Web.UI.WebControls.TreeView Treeview1;

/// <summary>
/// The following function adds two master levels and their
/// respective child nodes to the Treeview control
/// </summary>
public void PopulateTree()
{
   TreeNode nodeProdDetail, nodeProdMaster;
   nodeProdMaster      = new TreeNode();
   nodeProdMaster.Text = "Master1";
   nodeProdMaster.ID   = "1";

   nodeProdDetail             = new TreeNode();
   nodeProdDetail.Text        = "Detail1";
   nodeProdDetail.ID          = "1.1";
   nodeProdDetail.NavigateUrl = "SomePage.aspx";
   nodeProdMaster.Nodes.Add(nodeProdDetail);

   Treeview1.Nodes.Add(nodeProdMaster);

   nodeProdMaster      = new TreeNode();
   nodeProdMaster.Text = "Master2";
   nodeProdMaster.ID   = "2";

   nodeProdDetail             = new TreeNode();
   nodeProdDetail.Text        = "Detail2";
   nodeProdDetail.ID          = "2.1";
   nodeProdDetail.NavigateUrl = "SomeOtherPage.aspx";
   nodeProdMaster.Nodes.Add(nodeProdDetail);

   Treeview1.Nodes.Add(nodeProdMaster);
}