в 15:30, 26 мая 2010

2010-05-26T15:30:57Z

Admin: 1 версия

2010-05-26T11:57:00Z

1 версия

Новая страница

== A grid with an empty data source.==



<source lang="csharp">
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Empty Grid</title>
</head>
<body>
<div id="pageContent">
<form id="form1" runat="server">
<asp:SqlDataSource ID="SqlDataSource1" runat="server" EnableCaching="true"
ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
SelectCommand="SELECT customerid, companyname FROM customers WHERE customerid="none"">
</asp:SqlDataSource>
<asp:gridview ID="Gridview1" runat="server" datasourceid="SqlDataSource1">
<emptydatatemplate>
<asp:label ID="Label1" runat="server">
There"s no data to show in this view.
</asp:label>
</emptydatatemplate>
</asp:gridview>
</form>
</div>
</body>
</html></source>

== Use Linq-to-DataSets to query against (typed) DataTables and DataSets using the LINQ syntax==



<source lang="csharp">
<%@ Page Language="C#"
AutoEventWireup="true"
CodeFile="Default.aspx.cs"
Inherits="Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Linq-to-DataSets</title>
</head>
<body>
<form id="form1" runat="server">
<div id="pageContent">
<asp:Button ID="Button1" runat="server" Text="First 10 Days of Jan98" onclick="Button1_Click" />
<asp:GridView ID="GridView1" runat="server">
</asp:GridView>
</div>
</form>
</body>
</html>
File: Default.aspx.cs
using System;
using System.Data;
using System.Data.SqlClient;
using System.Collections;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Xml.Linq;
public partial class Default : System.Web.UI.Page
{
protected void Button1_Click(object sender, EventArgs e)
{
string connString = "SERVER=(local);DATABASE=northwind;Trusted_Connection=yes;";
string cmd = "SELECT * FROM customers;SELECT * FROM orders";
SqlDataAdapter adapter = new SqlDataAdapter(cmd, connString);
DataSet ds = new DataSet();
adapter.Fill(ds);
var customers = ds.Tables[0].AsEnumerable();
var orders = ds.Tables[1].AsEnumerable();
var data = from o in orders
join c in customers
on o.Field<string>("CustomerID") equals c.Field<string>("CustomerID")
where o.Field<DateTime>("OrderDate").Year == 1998 &&
o.Field<DateTime>("OrderDate").Month == 1 &&
o.Field<DateTime>("OrderDate").Day < 10
select new {OrderID=o.Field<int>("OrderID"),
Company=c.Field<string>("CompanyName")};
GridView1.DataSource = data;
GridView1.DataBind();
}
}</source>

== use Linq-to-Objects to query against .NET collections using the LINQ syntax==



<source lang="csharp">
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs"
Inherits="Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Linq-to-Objects</title>
</head>
<body>
<div id="pageContent">
<form id="form2" runat="server">
<asp:Button ID="Button1" runat="server" Text="Click" onclick="Button1_Click" />
</form>
</div>
</body>
</html>
File: Default.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Xml.Linq;
public partial class Default : System.Web.UI.Page
{
protected void Button1_Click(object sender, EventArgs e)
{
int[] fiboNumbers = new int[] { 0, 1, 1, 2, 3, 5, 8, 13, 21, 34 };
var data0 = from n in fiboNumbers
where n % 2 == 0
select n;
Response.Write(data0.Count());
Response.Write("<hr/>");
var data1 = (from n in fiboNumbers
where n % 2 == 0 && n <10
select n).Sum();
Response.Write(data1);
}
}</source>

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ASP.NET Tutorial/ADO.net Database/LINQ - История изменений

в 15:30, 26 мая 2010

Admin: 1 версия