Bind (Populate) ASP.Net GridView based on column name selected from ListBox using C# and VB.Net

Hi ilanocf,

Refer below sample.

Database

For this example I have used of Northwind database that you can download using the link given below.

Download Northwind Database

HTML

<table>
    <tr>
        <td>
            <asp:ListBox runat="server" ID="lstColumns" AutoPostBack="true"
                OnSelectedIndexChanged="OnSelectedIndexChanged" SelectionMode="Multiple">
                <asp:ListItem Text="text1" />
                <asp:ListItem Text="text2" />
            </asp:ListBox>
        </td>
        <td>
            <asp:ListBox runat="server" ID="lstSelectedColumns"></asp:ListBox>
        </td>
    </tr>
    <tr>
        <td colspan="2" align="center">
            <asp:Button Text="Search" runat="server" OnClick="OnSearch" /></td>
    </tr>
</table>
<asp:GridView runat="server" ID="gvCustomers"></asp:GridView>

Namespaces

C#

using System.Configuration;
using System.Data;
using System.Data.SqlClient;

VB.Net

Imports System.Configuration
Imports System.Data
Imports System.Data.SqlClient

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        lstColumns.DataSource = GetData("SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = N'Customers'");
        lstColumns.DataTextField = "COLUMN_NAME";
        lstColumns.DataValueField = "COLUMN_NAME";
        lstColumns.DataBind();
    }
}

private DataTable GetData(string query)
{
    string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(conString))
    {
        using (SqlCommand cmd = new SqlCommand(query, con))
        {
            using (SqlDataAdapter sda = new SqlDataAdapter(cmd))
            {
                using (DataTable dt = new DataTable())
                {
                    sda.Fill(dt);
                    return dt;
                }
            }
        }
    }
}

protected void OnSelectedIndexChanged(object sender, EventArgs e)
{
    lstSelectedColumns.Items.Clear();
    foreach (ListItem item in lstColumns.Items)
    {
        if (item.Selected)
        {
            lstSelectedColumns.Items.Add(new ListItem { Text = item.Text, Value = item.Value });
        }
    }
}

protected void OnSearch(object sender, EventArgs e)
{
    List<string> columns = new List<string>();
    foreach (ListItem item in lstSelectedColumns.Items)
    {
        columns.Add(item.Text);
    }
    string query = string.Format("SELECT TOP 5 {0} FROM Customers", string.Join(",", columns));
    gvCustomers.DataSource = GetData(query);
    gvCustomers.DataBind();
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        lstColumns.DataSource = GetData("SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = N'Customers'")
        lstColumns.DataTextField = "COLUMN_NAME"
        lstColumns.DataValueField = "COLUMN_NAME"
        lstColumns.DataBind()
    End If
End Sub

Private Function GetData(ByVal query As String) As DataTable
    Dim conString As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As SqlConnection = New SqlConnection(conString)
        Using cmd As SqlCommand = New SqlCommand(query, con)
            Using sda As SqlDataAdapter = New SqlDataAdapter(cmd)
                Using dt As DataTable = New DataTable()
                    sda.Fill(dt)
                    Return dt
                End Using
            End Using
        End Using
    End Using
End Function

Protected Sub OnSelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
    lstSelectedColumns.Items.Clear()
    For Each item As ListItem In lstColumns.Items
        If item.Selected Then
            lstSelectedColumns.Items.Add(New ListItem With {
            .Text = item.Text,
            .Value = item.Value
        })
        End If
    Next
End Sub

Protected Sub OnSearch(ByVal sender As Object, ByVal e As EventArgs)
    Dim columns As List(Of String) = New List(Of String)()
    For Each item As ListItem In lstSelectedColumns.Items
        columns.Add(item.Text)
    Next
    Dim query As String = String.Format("SELECT TOP 5 {0} FROM Customers", String.Join(",", columns))
    gvCustomers.DataSource = GetData(query)
    gvCustomers.DataBind()
End Sub

Screenshot