ASP.NET 日历未更新

Question

I'm adding a Calendar to to my application and am having a hard time updating the date. For some reason when I select a new date the previous date is displayed. So if it starts on the 11th and I select the 13th, the 11th is displayed again when the page reloads and then if I select the 14th after that the 13th will load.

I declare the calendar in the application like this:

    <asp:Calendar ID="myCal" runat="server"></asp:Calendar>

And then I have this code in page_init:

    myCal.SelectedDate = DateTime.Today.AddDays(1);

And use this in page_load:

    String date = myCal.SelectedDate.ToString("yyyyMMdd");

Thanks.

Answer 1

Your calendar probably triggers a postback, but the Page_Load event occurs before any control events. That means you are loading the "previous" selected value each time in the Page_Load method.

You should move your string date = myCal.SelectedDate.ToString("yyyyMMdd"); and its associated usage from the Page_Load to the SelectionChanged event handler for the calendar control.

So create the following method:

protected void myCal_SelectionChanged(Object sender, EventArgs e)
{
    string date = myCal.SelectedDate.ToString("yyyyMMdd");
    // lblMyLabel.Text = date;
    // Put your code that handles the selected date here.
}

And associate it with your calendar:

<asp:Calendar ID="myCal" runat="server"
    OnSelectionChanged="myCal_SelectionChanged"></asp:Calendar>