How to open a file by clicking on it in TreeView - winforms

Question

How do I open a file (ex. PDF) when I click the lowest child node in my tree.
I have created a TreeView program which is automatically filled by a database file.

Answer 1

Associate a path to that node, then use something like this:
private void LinkClicked(object sender, LinkClickedEventArgs e)
{
Process.Start(#".\" + "YOUR FILE NAME AND EXTENSION");
}
Read about: Process.Start
Starts a process resource by specifying the name of a document or application
file and associates the resource with a new System.Diagnostics.Process component.

Answer 2

You need to look at TreeNode Class
Example :
private void Form1_Load(object sender, EventArgs e)
{
//
// This is the first node in the view.
//
TreeNode treeNode = new TreeNode("Windows");
treeView1.Nodes.Add(treeNode);
//
// Another node following the first node.
//
treeNode = new TreeNode("Linux");
treeView1.Nodes.Add(treeNode);
//
// Create two child nodes and put them in an array.
// ... Add the third node, and specify these as its children.
//
TreeNode node2 = new TreeNode("C#");
TreeNode node3 = new TreeNode("VB.NET");
TreeNode[] array = new TreeNode[] { node2, node3 };
//
// Final node.
//
treeNode = new TreeNode("Dot Net Perls", array);
treeView1.Nodes.Add(treeNode);
}
Though example is not reading nodes from DB. You can do that writing a query to fetch nodes.Follow steps on following path , it will lead you from scratch
Create a TreeView from a Database in Windows Forms and C#
Example Source : Tree View
For opening file on Node click look at
public event TreeNodeMouseClickEventHandler NodeMouseClick
// If a node is double-clicked, open the file indicated by the TreeNode.
void treeView1_NodeMouseClick(object sender,
TreeNodeMouseClickEventArgs e)
{
try
{
System.Diagnostics.Process.Start(#"c:\" + e.Node.Text);//e.Node.Text contains fileName
}
// If the file is not found, handle the exception and inform the user.
catch (System.ComponentModel.Win32Exception)
{
MessageBox.Show("File not found.");
}