CODEWITHSUNDEEP
c#sqlvalidationdatetimepicker
Adax
Adax

Reputation: 47

Validating Age Not Under 18

How to show a error message if the person is under 18 years old? I use the following code, but it always displays that the age is invalid, even if I enter a date earlier than 1995.

DateTime dt = DateTime.Parse(dob_main.Text);
DateTime dt_now = DateTime.Now;

DateTime dt_18 = dt.AddYears(-18);

if (dt.Date >= dt_18.Date)
{
    MessageBox.Show("Invalid Birth Day");
}

Upvotes: 2

Views: 26639

Answers (8)

Muhammad Fahad Nadeem
Muhammad Fahad Nadeem

Reputation: 1142

Try this:

DateTime birthDate = DateTime.Parse(dob_main.Text);

if (IsAgeLessThan18Years(birthDate))
{
    MessageBox.Show("Invalid Birth Day");
}

bool IsAgeLessThan18Years(DateTime birthDate)
        {
            if (DateTime.Now.Year - birthDate.Year > 18)
            {
                return false;
            }
            else if (DateTime.Now.Year - birthDate.Year < 18)
            {
                return true;
            }
            else //if (DateTime.Now.Year - birthDate.Year == 18)
            {
                if (birthDate.DayOfYear < DateTime.Now.DayOfYear)
                {
                    return false;
                }
                else if (birthDate.DayOfYear > DateTime.Now.DayOfYear)
                {
                    return true;
                }
                else //if (birthDate.DayOfYear == DateTime.Now.DayOfYear)
                {
                    return false;
                }
            }
        }

Upvotes: 0

Luiz Fernando Corr&#234;a Leite
Luiz Fernando Corr&#234;a Leite

Reputation: 1035

try this:

private static int CalculateAge(DateTime dateOfBirth) 
{ 
   int age = 0;
   age = DateTime.Now.Year - dateOfBirth.Year;
   if (DateTime.Now.DayOfYear < dateOfBirth.DayOfYear) 
     age = age - 1;

   return age;
}

refer: https://naveed-ahmad.com/2010/01/08/calculating-age-from-date-of-birth-c/

Upvotes: 0

Gaspa79
Gaspa79

Reputation: 5689

One can achieve this by simply using this after parsing the date:

private static bool GreaterThan18(DateTime bornIn)
{
    return (bornIn.AddYears(18) >= DateTime.Now);    
}

Upvotes: 1

Terrell Hull
Terrell Hull

Reputation: 21

DateTime? BirthDate = DateTime.Parse(dob_main.Text);

if (BirthDate < DateTime.Now.AddYears(-18))
{
  MessageBox.Show("Invalid Birth Day");
}

Upvotes: 2

Nazir Ullah
Nazir Ullah

Reputation: 610

Simple use this way 

DateTime BirthDate   = DateTime.Parse(dob_main.Text);
DateTime CurrentDate = DateTime.Today;
int Age = CurrentDate.Year - BirthDate.Year;
if(Age < 18)
{
    MessageBox.Show("Invalid Birth Day");
}

Upvotes: -1

Ilya Ivanov
Ilya Ivanov

Reputation: 23626

You should try something along:

var age = GetAge(dt);
if(age < 18)
{
    MessageBox.Show("Invalid Birth Day");
}

int GetAge(DateTime bornDate)
{
    DateTime today = DateTime.Today;
    int age = today.Year - bornDate.Year;
    if (bornDate > today.AddYears(-age)) 
        age--;

    return age;
}

Offtopic note: consider naming your variables in such a way, that SO users can guess what is the intention of that variable by reading it. dt dob_main and dt_18 are far away from being good names.

Upvotes: 8

VsMaX
VsMaX

Reputation: 1785

DateTime dt = DateTime.Parse(dob_main.Text);
DateTime dt_now = DateTime.Now;

DateTime dt_18 = dt.AddYears(18); //here add years, not subtract

if (dt_18.Date >= dt_now.Date) //here you want to compare dt_now
{
    MessageBox.Show("Invalid Birth Day");
}

Upvotes: 7

Damith
Damith

Reputation: 63065

DateTime bday = DateTime.Parse(dob_main.Text);
DateTime today = DateTime.Today;
int age = today.Year - bday.Year;
if(age < 18)
{
    MessageBox.Show("Invalid Birth Day");
}

Upvotes: 5

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