Question

我在我的Windows应用程序中添加了一个实体，这是我的整个代码。

Imports MSWord.FirstBSEntities

Private db As FirstBSEntities

Private Sub btnOpen_Click(sender As System.Object, e As System.EventArgs) Handles btnOpen.Click
    AxEDOffice1.OpenFileDialog()
    Dim Count As Integer = AxEDOffice1.WordGetPageCount
    Dim Id As Integer = (From a In db.FirstBS Select a.BSId).FirstOrDefault()
    Label1.Text = Id * Count
End Sub

App.Config中

    <connectionStrings>
    <add name="FirstBSEntities" providerName="System.Data.SqlClient"
           connectionString="Data Source=SQL\SQL2008;Initial Catalog=FirstBS; Integrated Security=true" />
    <!--<add name="FirstBSEntities" connectionString="Data Source=SQL\SQL2008;Initial Catalog=FirstBSEntities;User ID=sa;Password=P@ssw0rd" providerName="System.Data.SqlClient" />-->
    <add name="FirstBSEntities" connectionString="metadata=res://*/Model1.csdl|res://*/Model1.ssdl|res://*/Model1.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=SQL\SQL2008;initial catalog=FirstBS;user id=sa;password=P@ssw0rd;multipleactiveresultsets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />
    </connectionStrings>

我是连接字符串的新手，我的linq

中出现了这个错误

Object reference not set to an instance of an object.

如何在vb.net中建立连接字符串？

0 个答案: