Display Images from Database on DropDownList change using C# and VB.Net in ASP.Net

Refer the below code.

HTML

<asp:TextBox runat="server" OnTextChanged="TextChanged" AutoPostBack="true" ID="txtId" />
<hr />
<asp:Image ID="Image1" runat="server" Visible="false" Height="150px" Width="150px" />

Code

C#

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

protected void TextChanged(object sender, EventArgs e)
{
    string id = txtId.Text.Trim();
    Image1.Visible = id != "0";
    if (id != "0")
    {
        byte[] bytes = (byte[])GetData("SELECT Data FROM tblFiles WHERE Id =" + id).Rows[0]["Data"];
        string base64String = Convert.ToBase64String(bytes, 0, bytes.Length);
        Image1.ImageUrl = "data:image/png;base64," + base64String;
    }
}

VB

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

Protected Sub TextChanged(sender As Object, e As EventArgs)
	Dim id As String = txtId.Text.Trim()
	Image1.Visible = id <> "0"
	If id <> "0" Then
		Dim bytes As Byte() = DirectCast(GetData(Convert.ToString("SELECT Data FROM tblFiles WHERE Id =") & id).Rows(0)("Data"), Byte())
		Dim base64String As String = Convert.ToBase64String(bytes, 0, bytes.Length)
		Image1.ImageUrl = Convert.ToString("data:image/png;base64,") & base64String
	End If
End Sub

Screenshot