使用JavaScript在ASP.NET中进行将来的日期验证

Question

Below mentioned code is been used to validate a future date, but it's not working. Any help is appreaciated. The textbox has readonly property set to false so i can change the values in the text box and change to the future date,for that condition i need to validate

// In aspx

  <asp:TextBox ID="txtdob" runat="server" OnClientDateSelectionChanged="checkDate"></asp:TextBox>

  <asp:Button ID="Button2" runat="server" onclick="Button2_Click" Height="26px" Width="23px" Text=".." />   
<script type="text/javascript" >
function checkDate(sender, args) 
{
    if (sender._selectedDate > new Date())
    {
        alert("You cannot select future date!");
        sender._selectedDate = new Date();
        // set the date back to the current date
        sender._txtdob.set_Value(sender._selectedDate.format(sender._format))
    }
}
</script>
<asp:Calendar ID="Calendar1" runat="server" onselectionchanged="Calendar1_SelectionChanged" OnClientDateSelectionChanged="checkDate"
   style="top: 320px; left: 246px; position: absolute; height: 188px; width: 259px">
</asp:Calendar>

//In c#

protected void Button2_Click(object sender, EventArgs e)
{
   Calendar1.Visible = true;
}
protected void Calendar1_SelectionChanged(object sender, EventArgs e)
{
   txtdob.Text = Calendar1.SelectedDate.ToShortDateString();
}

Answer 1

This solution is no validation per request, but it makes all dates not selectable

protected void Calendar1_DayRender(object sender, DayRenderEventArgs e)
{
    endDate = DateTime.Today;
    e.Day.IsSelectable = e.Day.Date <= endDate;
}

Note that DayRenderEventArgs is in the Namespace System.Web.UI.WebControls

Answer 2

OnClientDateSelectionChanged is not a valid method for asp calender control. It is a method used in ajax calender control. Check this link

http://forums.asp.net/t/1922747.aspx

Answer 3

First download Ajax Tool Kit which is free and then in Toolbox Add a New Tab then Choose items and browse for Ajax Control ToolKit dll file . The tool kit will added to the toolbox and then select a calendar extender from the ajax tool kit. Then in aspx page add this lines of code before the ContentPlaceHolder

 <%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="asp" %>

Then inside Content Place Holder add the JavaScript.

 <script type="text/javascript">
    function checkDate(sender, args) 
            {
                if (sender._selectedDate > new Date()) 
                {
                    alert("You cannot select future date!");
                    sender._selectedDate = new Date();
                    // set the date back to the current date
                    sender._textbox.set_Value(sender._selectedDate.format(sender._format))
                }
            }
</script>

And then for the textbox use this code.

   <asp:TextBox ID="txtdob" runat="server"  ></asp:TextBox>
         <asp:CalendarExtender runat="server" ID="CalenderExtender1" Format="MM/dd/yyyy" OnClientDateSelectionChanged="checkDate"
        TargetControlID="txtdob">
    </asp:CalendarExtender>

This might solve your issue.