我正在尝试使用 JavaScript 来验证所选日期不早于今天,但是当我选择今天的日期时,它会显示警报框。
JavaScript:
function checkDueDate(sender, args) {
    var td = new Date(); 
    td.setMinutes(59);
    td.setSeconds(59);
    td.setHours(23);
    //to move back one day
    td.setDate(td.getDate() - 1);
    if (sender._selectedDate < td) {
        alert("You can't select day from the past! " + td + "");
        sender._selectedDate = new Date();
        // set the date back to the current date
        sender._textbox.set_Value(sender._selectedDate.format(sender._format))
    }
ASP.NET:
        <asp:TextBox ID="txtDueDate" runat="server"></asp:TextBox>
        <asp:CalendarExtender ID="txtDueDate_CalendarExtender" runat="server" 
            TargetControlID="txtDueDate" OnClientDateSelectionChanged="checkDueDate">
        </asp:CalendarExtender>
