我有一个日历,可以在ASP中选择多个日期。问题在于,更改为其他月份后,Session [“ SelectedDates”]将为空(大概是因为以前的日期不在视图中)。这样可以避免我选择多个月份中的多个日期,因为其他月份中的日期将被清除。我该如何解决这个问题?
我一直试图在OnVisibleMonthChanged期间将日期存储在temp var中,但是我无法使代码正常工作。
private List<DateTime> datelist = new List<DateTime>();
protected void Calendar1_SelectionChanged(object sender, EventArgs e)
{
if (Session["SelectedDates"] != null)
{
List<DateTime> newList = (List<DateTime>)Session["SelectedDates"];
foreach (DateTime dt in newList)
{
if (Calendar1.SelectedDates.Contains(dt))
{
Calendar1.SelectedDates.Remove(dt);
}
else
{
Calendar1.SelectedDates.Add(dt);
}
}
datelist.Clear();
}
}
protected void Calendar1_DayRender(object sender, DayRenderEventArgs e)
{
if (e.Day.IsSelected == true)
{
datelist.Add(e.Day.Date);
}
Session["SelectedDates"] = datelist;
}
ASPX
<asp:Calendar NextPrevStyle-ForeColor="White" ClientIDMode="Static" ID="Calendar1" OnDayRender="Calendar1_DayRender" OnSelectionChanged="Calendar1_SelectionChanged" OnVisibleMonthChanged="Calendar1_VisibleMonthChanged"
runat="server" BorderWidth="1px"
DayNameFormat="Shortest">
</asp:Calendar>
答案 0 :(得分:0)
在您的日历中,似乎回传处理得不好,因为当您在日历中选择任何日期时,会调用 Calendar1_DayRender 并将 datelist 设置为null,因此会话将填充为null,因此在 Calendar1_SelectionChanged 中,会话的结果将返回 NULL 。您可以通过在 Calendar1_DayRender 函数上添加断点并监视其动作来进行检查。
答案 1 :(得分:0)
尝试一下,它正在努力选择跨月的多个日期。确保两个事件都已链接。
public static List<DateTime> dateList = new List<DateTime>();
protected void Calendar1_DayRender(object sender, DayRenderEventArgs e)
{
if (e.Day.IsSelected == true)
{
dateList.Add(e.Day.Date);
}
Session["SelectedDates"] = dateList;
}
protected void Calendar1_SelectionChanged(object sender, EventArgs e)
{
if (Session["SelectedDates"] != null)
{
List<DateTime> newList = (List<DateTime>)Session["SelectedDates"];
foreach (DateTime dt in newList)
{
Calendar1.SelectedDates.Add(dt);
}
dateList.Clear();
}
}
答案 2 :(得分:0)
我尝试过类似的操作,这可能会有用:
protected void C1_SelectionChanged(object sender, EventArgs e)
{
Label1.Text = "";
L1.Items.Add(C1.SelectedDate.ToShortDateString());
ListItem[] x = new ListItem[L1.Items.Count];
L1.Items.CopyTo(x, 0);
Session["x"] = x;
ListItem[] collection = (ListItem[])Session["x"];
foreach (var item in collection)
{
Label1.Text += item.Text + "</br>";
}
}
您可以尝试以下方法:
List<DateTime> lb = new List<DateTime>();
lb.Add(C1.SelectedDate);
DateTime[] a = lb.ToArray();
lb.CopyTo(a, 0);
Session["x"] = a;
DateTime[] collection = (DateTime[])Session["x"];
foreach (var item in collection)
{
Label1.Text += item.ToShortDateString() + "</br>";
}
答案 3 :(得分:0)
我发现处理此问题的更好方法是使用ViewState。我修改了https://sdevireddy.wordpress.com/2009/08/14/multiple-date-selection-in-asp-calendar/中的代码。每当更改选择时,我都会将ViewState传输到Session。然后可以从会话中获取日期。
public List<DateTime> SelectedDates
{
get
{
if (ViewState["Dates"] != null)
return (List<DateTime>)ViewState["Dates"];
else
return new List<DateTime>() { Calendar1.SelectedDate };
}
set
{
ViewState["Dates"] = value;
}
}
protected void Calendar1_SelectionChanged(object sender, EventArgs e)
{
foreach (DateTime selectedDate in Calendar1.SelectedDates)
{
if (SelectedDates.Contains(selectedDate))
SelectedDates.Remove(selectedDate);
else
SelectedDates.Add(selectedDate);
}
ViewState["Dates"] = SelectedDates;
Session["SelectedDates"] = ViewState["Dates"];
}
protected void Calendar1_PreRender(object sender, EventArgs e)
{
Calendar1.SelectedDates.Clear();
foreach (DateTime dt in SelectedDates)
Calendar1.SelectedDates.Add(dt);
}