Retrieves, or generates code to retrieve, values from the <
connectionStrings> section of the Web.config file.
Namespace: System.Web.Compilation
Assembly: System.Web (in system.web.dll)
Visual Basic (Declaration)
Public Class ConnectionStringsExpressionBuilder
Inherits ExpressionBuilder
Dim instance As ConnectionStringsExpressionBuilder
public class ConnectionStringsExpressionBuilder : ExpressionBuilder
public ref class ConnectionStringsExpressionBuilder : public ExpressionBuilder
public class ConnectionStringsExpressionBuilder extends ExpressionBuilder
public class ConnectionStringsExpressionBuilder extends ExpressionBuilder
The ConnectionStringsExpressionBuilder class provides access to values in the <connectionStrings> section of the Web.config file. The <connectionStrings> section of the Web.config file contains connection string values in name/value pairs.
A connection string value is retrieved by assigning an expression of the form
<%$ ConnectionStrings: secureConnectionString %>
to a control property. The part of the expression before the colon (:) designates the type of expression to be retrieved, and the part after the colon signifies the name of the connection string. The preceding expression would retrieve the following value from the Web.config file.
<connectionStrings>
<add name="secureConnectionString" connectionString="Data
Source=localhost;Integrated Security=SSPI;Initial
Catalog=Northwind;" providerName="System.Data.SqlClient" />
</connectionStrings>
When the page parser encounters an expression with the prefix ConnectionStrings, it creates an instance of the ConnectionStringsExpressionBuilder class to handle the expression.
If the expression is encountered in a page that will be compiled, the ConnectionStringsExpressionBuilder object generates code that retrieves the specified connection string from the Web.config file. If the expression is encountered in a page that will not be compiled, the ConnectionStringsExpressionBuilder object returns the value from the Web.config file when the page is parsed.
The following code example demonstrates how to declaratively use a SqlDataSource control to retrieve data from a computer running Microsoft SQL Server and display it in a GridView control.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:SqlDataSource
id="SqlDataSource1"
runat="server"
DataSourceMode="DataReader"
ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
SelectCommand="SELECT FirstName, LastName, Title FROM Employees">
</asp:SqlDataSource>
<asp:GridView
id="GridView1"
runat="server"
DataSourceID="SqlDataSource1">
</asp:GridView>
</form>
</body>
</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:SqlDataSource
id="SqlDataSource1"
runat="server"
DataSourceMode="DataReader"
ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
SelectCommand="SELECT FirstName, LastName, Title FROM Employees">
</asp:SqlDataSource>
<asp:GridView
id="GridView1"
runat="server"
DataSourceID="SqlDataSource1">
</asp:GridView>
</form>
</body>
</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:SqlDataSource
id="SqlDataSource1"
runat="server"
DataSourceMode="DataReader"
ConnectionString="Data Source=localhost;Integrated Security=SSPI;Initial Catalog=Northwind;"
SelectCommand="SELECT FirstName, LastName, Title FROM Employees">
</asp:SqlDataSource>
<asp:GridView
id="GridView1"
runat="server"
DataSourceID="SqlDataSource1">
</asp:GridView>
</form>
</body>
</html>
The code retrieves the following connection string from the Web.config file.
<configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">
<connectionStrings>
<add name="MyNorthwind" connectionString="Data
Source=localhost;Integrated Security=SSPI;Initial
Catalog=Northwind;" providerName="System.Data.SqlClient" />
</connectionStrings>
</configuration>
System.Object
System.Web.Compilation.ExpressionBuilder
System.Web.Compilation.ConnectionStringsExpressionBuilder
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.
.NET Framework
Supported in: 3.0, 2.0