frmconnection.vb

Visual Basic 传统数据访问模式ADO

Option Explicit On
Option Strict On
Imports ADODB
Public Class frmConnection

    Private oConnection1 As Connection
    Private Sub btnConnection_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnConnection.Click

        '设置数据库连接字符串
        Dim m_sConnStr As String = "Provider='SQLOLEDB';Data Source='HZIEE-2E53F913F';" & _
                    "Initial Catalog='SuperMarket';Integrated Security='SSPI';"

        '实例化Connection类并打开Connection对象
        oConnection1 = New Connection
        oConnection1.CursorLocation = CursorLocationEnum.adUseClient
        oConnection1.Open(m_sConnStr)

        '根据数据库是否连接成功，显示相应的信息
        If oConnection1.State = ConnectionState.Open Then
            lbDisplay.Text = "连接数据库成功！"
        Else
            lbDisplay.Text = "连接数据库失败！"
        End If

        '改变按钮的状态
        btnConnection.Enabled = False
        btnClose.Enabled = True

    End Sub

    Private Sub btnClose_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClose.Click
        '判断Connection对象是否存在
        If Not oConnection1 Is Nothing Then
            '判断数据库是否处于连接状态
            If oConnection1.State = ConnectionState.Open Then
                '关闭数据库连接
                oConnection1.Close()
                lbDisplay.Text = "关闭数据库连接！"
            End If
            oConnection1 = Nothing
        End If

        '改变按钮的状态
        btnConnection.Enabled = True
        btnClose.Enabled = False
    End Sub
End Class