Dim dts As DataSet
dts = QueryData()
  '查询方法,其返回值为DataSet
        For i As Integer = 0 To dts.Tables(0).Rows.Count - 1
            comboBox.Items.Add(dtsNation.Tables(0).Rows(i)(1))
    'comboBox为ComboBox控件名
        Next
        If comboBox.Items.Count <> 0 Then
            comboBox.SelectedIndex = 0
        End If
大概是这样。。。记不太清