使用while循环，来取DataReader的值，且把他封装正页面table

目的：封装成页面table，以字符串的形式返回给request

 '将查询的结果写到table中，用于popup显示

        Dim temptable As String = "<table border='0' cellpadding='0' cellspacing='1' style ='background-color:#C0FFFF;width:100%;'>"
’循环行数
        While Dr.Read()
‘循环列数

            For i As Integer = 0 To Dr.FieldCount - 1
                Dim value As String

                If System.Convert.IsDBNull(Dr.GetValue(i)) Then

                    value = "null"
                Else
‘取出该列的值
                    value = Dr.GetValue(i).ToString

                End If
                temptable = temptable + "<tr style='height:20px;'>"
’取出该列的列名字
                temptable = temptable + "<td width='150px' align='center' style ='background-  color:LightGoldenrodYellow'>" + Dr.GetName(i).ToString() + "</td>"
                temptable = temptable + "<td width='150px' align='center'>" + value + "</td>"
                temptable = temptable + "</tr>"
            Next

        End While
        Dr.Close()
        conn.Close()

        temptable += "<table>"