主题：起止页如何自动生成

Dim drs As List(Of DataRow) = DataTables("表A").Select("第三列 is not null", "_Sortkey")

For i As Integer = 0 To drs.count - 1
    Dim dr As DataRow = drs(i)
    If i = 0 Then
        dr("第四列") = "1-" & dr("第三列")
    ElseIf i = drs.count-1 Then
        dr("第四列") = dr("第三列") & "-" & dr("第三列")
    Else
        dr("第四列") = dr("第三列") & "-" & drs(i+1)("第三列")-1
    End If
Next

单独做一个按钮生成

Dim drs As List(Of DataRow) = DataTables("目录").Select("页号 is not null", "页号")

For i As Integer = 0 To drs.count - 1
    Dim dr As DataRow = drs(i)
    If i = drs.count-1 Then
        dr("起止页") = val(dr("页号")) & "-" & val(dr("页号"))
    Else
        dr("起止页") = val(dr("页号")) & "-" & val(drs(i+1)("页号"))-1
    End If
Next

如果写到datacolchanged，就这样写

If e.DataCol.name = "页号" Then
    If e.DataRow.IsNull("页号") Then
        e.DataRow("起止页") = Nothing
    Else
        Dim fdr As DataRow = DataTables("目录").find("页号 < '" & e.DataRow("页号") & "'", "页号 desc")
        If fdr IsNot Nothing
            fdr("起止页") = val(fdr("页号")) & "-" & val(e.DataRow("页号"))-1
        End If
        fdr = DataTables("目录").find("页号 > '" & e.DataRow("页号") & "'", "页号")
        If fdr Is Nothing Then
            e.DataRow("起止页") = val(e.DataRow("页号")) & "-" & val(e.DataRow("页号"))
        Else
            e.DataRow("起止页") = val(e.DataRow("页号")) & "-" & val(fdr("页号"))-1
        End If
    End If
End If