To get started then let’s go ahead and add a new item in your website application in Visual Studio 2008 or VWD Express 2008. To do this, just right click on the web site -> select Add New Item -> and on the Templates select LINQ to SQL Classes as shown below and click ok:
Now open up Server Exporer in Visual Studio and do the follwing:
* Under Data Connections, expand the northwind database
* Expand the Table folder and select the Table that you want to use and drag it on the Data Context. Note that I used the product table in this example as shown below:
Now add a new webform then grab a ListBox and a DropDownList control from the Visual Studio ToolBox and place it on the ASPX source. The mark up would look something like this:
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>LINQ Basics Demo</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ListBox ID="ListBox1" runat="server"></asp:ListBox>
<asp:DropDownList ID="DropDownList1" runat="server">
</asp:DropDownList>
</div>
</form>
</body>
</html>
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And here are the code blocks below for binding the ListBox and DropDownList control using LINQ:
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
public partial class LINQDemo : System.Web.UI.Page
{
private void ShowProducts()
{
//create new instance of the the DataContext class that we have just created
DataClassesDataContext db = new DataClassesDataContext();
FillListBox(db);
}
private void FillListBox(DataClassesDataContext db)
{
//LINQ syntax
//Select the ProductID and ProductName from Products
var products = from c in db.Products
select new
{
ProductID = c.ProductID,
ProductName = c.ProductName,
};
//Bind the ListBox
ListBox1.DataSource = products;
ListBox1.DataTextField = "ProductName";
ListBox1.DataValueField = "ProductID";
ListBox1.DataBind();
//Bind the DropDownList
DropDownList1.DataSource = products;
DropDownList1.DataTextField = "ProductName";
DropDownList1.DataValueField = "ProductID";
DropDownList1.DataBind();
}
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
ShowProducts();
}
}
}
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