我相信您会收到此错误，因为OleDbDataAdpater的构造函数需要两个字符串，而您的connection变量不是字符串.我怀疑您的代码需要如下所示:

I believe you are getting the error as the constructor for OleDbDataAdpater is expecting two strings and your connection variable isn't a string. I suspect your code needs to look like this:

Dim connection As readini = New readini()
Dim ConnString = connection.getConnectionString()

Dim sql As String = "SELECT * FROM tblPerson"
Dim da As New OleDbDataAdapter(sql, ConnString)
Dim ds As New DataSet()
da.Fill(ds, "tblPerson")
DataGridView1.DataSource = ds
DataGridView1.DataMember = "tblPerson"

getConnectionString方法还需要修改以添加Return语句:

The getConnectionString method also needed amending to add the Return statement:

Public Function getConnectionString() As String

    Dim s As String =
        "Provider=" & provider & ";" &
        "user ID=" & username & ";" &
        "password=" & password & ";" &
        "initial catalog=" & databasename & ";" &
        "data source=" & servername & "; " &
        "Persists Security Info=False"
    Return s
End Function