TreeView Control Populating with SqlDataSource

Description:

The article demonstrates how to populate TreeView Control using SqlDataSource at runtime in C#.NET. We can achieve intended result by simply executing SqlCommand Object either by ExecuteReader or ExecuteNonQuery method.

The TreeView control has a Nodes collection with root TreeNode objects. Each TreeNode in turn has its own Nodes collection that holds more than one child TreeNode.

<TreeNode object>.Nodes.Add (TreeNode node) method adds a new tree node with the specified text to the end of the current tree node collection

Procedure:

Step 1: Declaration of Connection, Command, and DataReader object

 SqlConnection Conn = new SqlConnection("Data Source=.\\SQLExpress;
                                                Initial Catalog=NorthWind; Integrated Security=True");
          SqlDataReader rdr;
          SqlCommand cmd;

Listing 1

Step 2: Now, whatever the code required to written for populating the SqlDataSource to the TreeView Control you can place it either into the click, load etc. event handlers.

Step 3: We need to create two TreeNode Objects as follows

TreeNode parent = treeView1.Nodes.Add("Suppliers");
TreeNode child;

Listing 2

Step 4: Now pass the SqlQuery as an argument of SqlCommand Object and stored the values into SqlDataReader Object.

cmd = new SqlCommand("SqlQuery", Conn);
Conn.Open();
rdr = cmd.ExecuteReader();

Listing 3

Step 5: Now retrieve the values from SqlDataReader and adds it to the Child Nodes of Nodes Collection of TreeView Control.

 while (rdr.Read())
{
         child = parent.Nodes.Add("Supplier ID: " + rdr.GetValue(0).ToString());
         child.Nodes.Add("Name: " + rdr.GetValue(1).ToString());
           
}

Listing 4


Intended Result:



Figure 1

Summary:

In this article, we discussed how we can populate a DataTable from the SqlDataSource into TreeView Control in C#.

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