您的参与将给我莫大的鼓励！！！vb中基础的基础！！
Dim cnn As New Connection
Dim rst As New Recordset

Private Sub Command1_Click()
Set DataGrid1.DataSource = Adodc1 '数据赋值给DataGrid1控件
'cnn.Close
End Sub

Private Sub Command2_Click()
cnn.ConnectionString = "Provider = Microsoft.Jet.OLEDB.4.0;" & "Data Source = " + App.Path + "\db.mdb"
If cnn.State <> adStateClosed Then cnn.Close
cnn.Open
Call 添加
rst.CursorLocation = adUseClient
rst.Open "select * from 职工信息表", cnn
Set DataGrid2.DataSource = rst
'cnn.Close
End Sub


Sub 添加()
sql = "select * from 职工信息表"
rst.Open sql, cnn, adOpenKeyset, adLockOptimistic
If Not rst.EOF Or Not BOF Then
rst.AddNew
rst("姓名") = Text1.Text
rst.Update
End If
rst.Close
'cnn.Close
End Sub

在窗口中第一次添加数据时，能在datagrid控件上显示，但是再一次添加数据时，却发生错误！vb系统提示如下：
实时错误'3705':
对象打开时，不允许操作。
调试时，提示错误如下：cnn.ConnectionString = "Provider = Microsoft.Jet.OLEDB.4.0;" & "Data Source = " + App.Path + "\db.mdb"

敬请给位高手留下您的足迹，这是为什么啊？？？？叫等！！！！


[解决办法]
If cnn.State <> adStateClosed Then cnn.Close
cnn.ConnectionString = "Provider = Microsoft.Jet.OLEDB.4.0;" & "Data Source = " + App.Path + "\db.mdb"
换个位置