删除时自动递减行序列号

Question

我在gridview中使用此代码进行行删除。它应该是这样的“当它删除一行时，取第5行，序列号为5，行号6的串行字段应该变为5.意味着在删除一行后减少序列号。”但是当我用序列号5删除第5行时，它没有发生，第6行保持不变。

Protected Sub GridView1_RowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
        For Each control As Control In e.Row.Cells(0).Controls
            Dim DeleteButton As LinkButton = TryCast(control, LinkButton)
            If DeleteButton IsNot Nothing AndAlso DeleteButton.Text = "Delete" Then
                DeleteButton.OnClientClick = "return(confirm('Are you sure you want to delete this record?'))"
            End If
        Next
    End Sub

Protected Sub GridView1_RowCommand(ByVal sender As Object, ByVal e As GridViewCommandEventArgs)
    If e.CommandName = "Delete" Then
        ' get the categoryID of the clicked row

        Dim Serial As Integer = Convert.ToInt32(e.CommandArgument)
        ' Delete the record 
        Dim mycommand As New SqlCommand("DELETE FROM target WHERE SlNo = '" & Serial & "'", con)
        con.Open()
        mycommand.ExecuteNonQuery()
        con.Close()
        bindphoto2()
        Label1.Text = "File has been deleted succefully"
    End If
End Sub
Protected Sub GridView1_RowDeleting(ByVal sender As Object, ByVal e As GridViewDeleteEventArgs)
    Dim Serial As Integer = CInt(GridView1.DataKeys(e.RowIndex).Value)
    Dim mycommand As New SqlCommand("DELETE FROM target WHERE SlNo = '" & Serial & "'", con)
    con.Open()
    mycommand.ExecuteNonQuery()
    con.Close()