阻止用户输入大于C＃的起始日期

Question

I am searching data based on two dates a from field and a To field in Asp.net

I want to prevent the user from entering a From date greater than a To date and display a message to the user Please select a valid date range

  DateTime InvoiceDateFrom = new DateTime();
DateTime InvoiceDateTo = new DateTime();

if (TxtInvoiceDateFrom.Text.Trim() != "")
{

  //DateTime FromDate = DateTime.ParseExact(TxtInvoiceDateFrom.Text.Trim(), "dd/MM/yyyy", null).AddDays(1);
  InvoiceDateFrom = Convert.ToDateTime(TxtInvoiceDateFrom.Text);
  //DateTime toDate = DateTime.ParseExact(TxtInvoiceDateTo.Text.Trim(), "dd/MM/yyyy", null).AddDays(1);

}

if (TxtInvoiceDateTo.Text.Trim() != "")
{
  InvoiceDateTo = Convert.ToDateTime(TxtInvoiceDateTo.Text);
}

Answer 1

if (InvoiceDateTo < InvoiceDateFrom)
    MessageBox.Show("Please select a valid date range.");

Answer 2

 DateTime x = DateTime.Parse("12/8/2012");   //as "12/8/2012" is the your specified date
 dateTimePicker1.MaxDate = x; // or you can use it in one line

if you want to prevent the user to choose date greater than today:

dateTimePicker1.MaxDate = DateTime.Today;

Answer 3

Please see if this is of help! C# way of doing is fine. But i would rather suggest javascript.

DateTime toDate=DateTime.ParseExact(todateString,"dd/MM/yy",System.Globalization.InvariantCulture);
DateTime fromDate=DateTime.ParseExact(fromdateString,"dd/MM/yy",System.Globalization.InvariantCulture);

int comparison=DateTime.Compare(toDate,fromDate);

if(comparison>=0)
{
     //Post custom error message.
}