与数据库连接出现“未将对象引用设置到对象的实例”的错误，代码如下

[anika]

Public dbConnection As New OleDbConnection()
Public dbAdapter As New OleDbDataAdapter()
Public DateSet As New DataSet()

Private Sub MainWnd_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
dbConnection.ConnectionString = ("Provider=SQLOLEDB.1;User ID=abc;Initial Catalog=database;Data Source=Localhost;Password=")
dbConnection.Open()

dbAdapter.SelectCommand.Connection = dbConnection /*这行出错*/

dbAdapter.SelectCommand.CommandText = "select * from OutInvoice " & " order by sn"
dbAdapter.SelectCommand.CommandType = CommandType.Text
dbAdapter.SelectCommand.ExecuteNonQuery()
dbAdapter.Fill(DateSet)
DataGrid1.DataSource = DateSet
End Sub

[timmy3310]

出错行前面加上：

dbAdapter.SelectCommand = New OleDbCommand()

[anika]

天哪，书上的代码竟然会漏了这一句
居然还是外国人写的

[dllgdx2000]

Command要NEW下

[zwztu]

唉！老外写的不一定对呀！！！！！

[xumahua]

抽他丫挺的！！！

[li_new]

也可以写成这样：
dim dbAdapter As New OleDbDataAdapter("select * from OutInvoice " & " order by sn"
,dbConnection)