ASP.NET validator for comparing two differences by date no more than 12 months

Question

I have two elements TextBoxfor entering a start and end date for a date. I must confirm that the end date is not more than the start date, and the difference between the start date and the end date is not more than 12 months.

Answer 1

For this you will need to use CustomValidator. In your markyou you will have something like this:

<asp:TextBox ID="txbStartDate" runat="server" />
<asp:TextBox ID="txbEndDate" runat="server" />
<asp:CustomValidator OnServerValidate="ValidateDuration"
    ErrorMessage="Dates are too far apart" runat="server" />

And in your code behind you define a validation handler:

protected void ValidateDuration(object sender, ServerValidateEventArgs e)
{
    DateTime start = DateTime.Parse(txbStartDate.Text);
    DateTime end = DateTime.Parse(txbEndDate.Text);

    int months = (end.Month - start.Month) + 12 * (end.Year - start.Year);

    e.IsValid = months < 12.0;
}

, . , , , ValidateDuration , , .

, , , ( ) . , , .

<asp:CompareValidator Operator="GreaterThanEqual" Type="Date"
    ControlToValidate="txbEndDate" ControlToCompare="txbStartDate"
    ErrorMessage="Let get started first!" runat="server" />

Answer 2

Timespan:

        DateTime start = DateTime.Parse(DateBegin.Text);
        DateTime end = DateTime.Parse(DateEnd.Text);
        TimeSpan ts = end - start;
        e.IsValid = ts.Days < 365;

Answer 3

: , - ( ) .

Answer 4

And why aren't you talking about this

 DateTime start = DateTime.Parse(DateBegin.Text);
 DateTime end = DateTime.Parse(DateEnd.Text);
 e.IsValid = (end-start).Years <1;