页面生成后，点击查询按钮，偶尔提示：已添加了具有相同键的项

添加的与主键有关的内容如蓝色代码所示，AddContent是不需要设置主键的，所以没找到有重复的键的项，问题到底出在哪里呢？

Dim cmd As new SQLCommand

cmd.C

cmd.CommandText = str

Dim dt As DataTable

dt = cmd.ExecuteReader

With wb.AddTabBar("", "tb1", 0)

    .AddPage("page1","列表项","./images/button.png")

    .AddPage("page2","表格","./images/msg.png")

End With

With wb.AddTable("page2","Table1")

    .CreateFromDataTable(dt)

End With

With wb.AddArticle("page1","ar1")

    For i As Integer = 0 To dt.datarows.count - 1

        Dim dr As DataRow = dt.datarows(i)

        .AddContent("<br/><b>合同编号:</b> " & dr("合同编号"))

        .AddContent("<b>合同名称:</b> " & dr("合同名称"))

            For Each dc As DataCol In dt.datacols

                If dc.name <> "合同编号" And dc.name <> "合同名称" Then

                    .AddContent("<b>" & dc.name & ": </b>" & dr(dc.name))

                End If

            Next

        .AddContent("<a href=\'./ContractsInfo/" & dr("合同编号") & ".pdf\'>单击此处</a>下载pdf文档(5M)")

        .AddContent("- - - - - - - - - 第" & i+1 & "条/共" & dt.datarows.count & "条 - - - - - - - - -")

    Next

End With

wb.AppendHTML("<style>Table.fox_table {text-align: center}</style>")

e.WriteString(wb.Build) \'生成网页