Vb.net Ado.net SqlConnection打开方法

我正在学习ADO.NET，但对我来说很难。。。我不明白为什么会出现此编译器错误： 连接.Open（）需要“声明”

我写这个代码

Imports System
Imports System.Data
Imports System.Data.SqlClient

Public Class Basics

    Dim connection As SqlConnection = DataConnection.GetConnectToSql

    ' Here the error: "Declaration expected"
    connection.Open()


End Class

Imports System.Data.SqlClient

Public Class DataConnection

    ' SQL Server Connection
    Dim connection As SqlConnection = DataConnection.GetConnectToSql

    ' SQL Server Connection with connectionString method
    Public Shared Function GetConnectToSql() As SqlConnection
        Dim connectionString As String =
            "Data Source=localhost\sqlexpress;Initial Catalog=Payables;" &
            "Integrated Security=True"
        Return New SqlConnection(connectionString)
    End Function

End Class

---

您试图在方法或属性之外执行功能

Imports System
Imports System.Data
Imports System.Data.SqlClient

Public Class Basics
    Private connection As SqlConnection = DataConnection.GetConnectToSql

    Public Sub Open()
        connection.Open()
    End Sub
End Class

Public Class DataConnection
    ' SQL Server Connection
    Private connection As SqlConnection = GetConnectToSql()

    ' SQL Server Connection with connectionString method
    Public Shared Function GetConnectToSql() As SqlConnection
        Dim connectionString As String = _
            "Data Source=localhost\sqlexpress;Initial Catalog=Payables;" & _
            "Integrated Security=True"
        Return New SqlConnection(connectionString)
    End Function
End Class