Introduction:
Here, I will explain how to populate
or bind dropdown list control from database in asp.net using c# and vb.net. This article will be useful for beginners.
Demo:
Steps to follow:
Create table in database:
Create Table “Student_Info” in Database “Blog” and Enter some data to
display.
Column Name
|
DataType
|
Student_Id
|
Int
|
Student_name
|
Varchar(100)
|
Age
|
Int
|
Class
|
Varchar(100)
|
Create
connection string in webconfig file:
<connectionStrings>
<add name="con" connectionString="Data Source=localhost; initial
catalog=Blog; integrated Security=true"></add>
</connectionStrings>
Design
Asp.Net webForm:
<fieldset style="width:350px;"><legend>Bind DropDownList
In ASP.NET</legend>
<table >
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td>Select Student:</td>
<td> <asp:DropDownList ID="ddlStudent" runat="server" Width="220px"></asp:DropDownList>
</td>
<td> </td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td> </td>
<td><asp:Button ID="btnSubmit" runat="server" Text="Show
Selected Student" OnClick="btnSubmit_Click" />
</td>
<td> </td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td>Selected Student: </td>
<td> <asp:Label ID="lblStudent" runat="server" Text=""></asp:Label>
</td>
<td> </td>
</tr>
</table>
</fieldset>
|
Asp.Net
Code:
Using
C#:
//add following napespaces
using
System.Configuration;
using System.Data;
using
System.Data.SqlClient;
//write following code
public partial class DropDownList : System.Web.UI.Page
{
SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["con"].ConnectionString);
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack)
{
Bind_Dropdown();
}
}
protected void btnSubmit_Click(object sender, EventArgs e)
{
if (ddlStudent.SelectedIndex > 0)
{
lblStudent.Text =
ddlStudent.SelectedItem.Text;
}
}
//bind dropdown
public void Bind_Dropdown()
{
if (con.State == ConnectionState.Closed)
{
con.Open();
}
SqlCommand cmd = new SqlCommand("select *
from student_info", con);
SqlDataAdapter adpData = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
adpData.Fill(dt);
ddlStudent.DataSource = dt;
ddlStudent.DataTextField = "Student_name";
ddlStudent.DataValueField = "Student_id";
ddlStudent.DataBind();
ddlStudent.Items.Insert(0,"Select
Student");
con.Close();
}
}
|
Using
VB.Net:
'Import Following
namespaces
Imports
System.Configuration
Imports System.Data
Imports
System.Data.SqlClient
'Write following Code
Private con As New SqlConnection(ConfigurationManager.ConnectionStrings("con").ConnectionString)
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
If Not IsPostBack Then
Bind_Dropdown()
End If
End Sub
Protected Sub
btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.Click
If
ddlStudent.SelectedIndex > 0 Then
lblStudent.Text =
ddlStudent.SelectedItem.Text
End If
End Sub
Public Sub Bind_Dropdown()
If con.State = ConnectionState.Closed Then
con.Open()
End If
Dim cmd As New SqlCommand("select *
from student_info", con)
Dim adpData As New SqlDataAdapter(cmd)
Dim dt As New DataTable()
adpData.Fill(dt)
ddlStudent.DataSource = dt
ddlStudent.DataTextField = "Student_name"
ddlStudent.DataValueField =
"Student_id"
ddlStudent.DataBind()
ddlStudent.Items.Insert(0, "Select
Student")
con.Close()
End Sub
End Class
|
