為了開具發(fā)票，我通過將選定的時間表存儲在瀏覽器會話中并在用戶更新時向該列表添加/刪除條目來跟蹤與發(fā)票關聯(lián)的時間表條目：GridView 加載所選公司的所有時間表，然后通過更改行樣式和選擇按鈕文本進行指示：private void HighlightInvoiceTimesheets(){    var timesheets = Session["invoiceTimesheets"] as List<Timesheet>;    var invoiceTotalHours = 0;    foreach (var timesheet in timesheets)    {        var tid = timesheet.Id.ToString();        foreach (GridViewRow row in ItemsGrid.Rows)        {            var btn = row.Cells[ItemsGrid.Columns.Count - 1].Controls[0] as LinkButton;            if (ItemsGrid.DataKeys[row.RowIndex].Values["Id"].ToString() == tid)            {                row.CssClass = "success";                btn.Text = "Remove";                int.TryParse(row.Cells[5].Text, out int timesheetHours);                invoiceTotalHours += timesheetHours;            }        }    }    Session["invoiceTotalHours"] = invoiceTotalHours;    BillableHoursLabel.Text = invoiceTotalHours.ToString();}當用戶在 GridView 中“選擇”一個項目時，它會在 Session 的集合中添加或刪除該項目，并相應地更新 GridView：protected void ItemsGrid_SelectedIndexChanging(object sender, GridViewSelectEventArgs e){    // Get the list of timesheets associated with the invoice.    var list = (Session["invoiceTimesheets"] == null) ? new List<Timesheet>() : Session["invoiceTimesheets"] as List<Timesheet>;    // Get the selected timesheet.    int.TryParse(ItemsGrid.DataKeys[e.NewSelectedIndex].Values["Id"].ToString(), out int timesheetId);    var timesheet = timesheetService.GetClearTimesheet(timesheetId);    // Get the select button to update its text.    var btn = ItemsGrid.Rows[e.NewSelectedIndex].Cells[ItemsGrid.Columns.Count - 1].Controls[0] as LinkButton;    // Get the total hours billable for the invoice based on the total hours of the timesheets.    var invoiceTotalHours = (Session["invoiceTotalHours"] == null) ? 0 : int.Parse(Session["invoiceTotalHours"].ToString());}這沒有任何錯誤，但我很困惑為什么list.Remove(timesheet);實際上不更新內(nèi)存中的列表。因此，會話中的集合不會更新，所做的更改也不會反映在數(shù)據(jù)庫中。