web.config中的文件如下：

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<appSettings> 
    <add key="constring"  value="integrated security=SSPI;data source=localhost;initial catalog=教务管理系统" />
</appSettings>

<system.web>

。。。。。。。。。

 </system.web>

</configuration>

访问如下：

 Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        '在此处放置初始化页的用户代码
        If Not IsPostBack Then
            Dim str As String = ConfigurationSettings.AppSettings("constring")
            Dim con As New SqlClient.SqlConnection(str)
            da.SelectCommand.Connection = con
            da.Fill(daset, "课程信息")
            dagrid.DataSource = daset.Tables("课程信息")
            dagrid.DataBind()
        End If
    End Sub