application

-accept birthday from user, it will probably easier to ask year , then month then day rather than parsing string reliably -calculate age of tghe user
-check to see if the age of hte user imposible . fo eg: if the user is not born output an errror message . if the user claims to be 135 yrs old then let then know thats not possible
-output the age of the user
-if it is the user's birthday , output nice messages

hint; lookup the system.datetime structure ....

It's assumed you have 3 textboxes (for year, month and day) on your form plus a button to calculate the age.

Try adding this code to the button's Click handler:

private void button1_Click(object sender, EventArgs e)

{

DateTime dob;

try

{

int year = int.Parse(textBox1.Text);

int month = int.Parse(textBox2.Text);

int day = int.Parse(textBox3.Text);

dob = new DateTime(year, month, day);

}

catch // catches any exception

{

MessageBox.Show("Not a valid date. Please amend");

textBox1.Focus();

return;

}

DateTime today = DateTime.Today;

if (today < dob)

{

MessageBox.Show("User hasn't been born yet! Please amend");

textBox1.Focus();

return;

}

int age;

if(today.Month > dob.Month || (today.Month == dob.Month && today.Day >= dob.Day))

{

age = today.Year - dob.Year;

}

else

{

age = today.Year - dob.Year - 1;

}

if(age >= 135)

{

MessageBox.Show("User can't be as old as this! Please amend");

textBox1.Focus();

return;

}

string message = "Age is " + age;

if (today.Month == dob.Month && today.Day == dob.Day)

{

message += "\r\n\r\nToday's your birthday. Many happy returns!";

}

MessageBox.Show(message);

}

1 Reply

Know the answer? Post it — somebody with the same question will find it here.

Vulpes13y ago
Accepted answer
It's assumed you have 3 textboxes (for year, month and day) on your form plus a button to calculate the age.

Try adding this code to the button's Click handler:

private void button1_Click(object sender, EventArgs e)
{
DateTime dob;

try
{
int year = int.Parse(textBox1.Text);
int month = int.Parse(textBox2.Text);
int day = int.Parse(textBox3.Text);
dob = new DateTime(year, month, day);
}
catch // catches any exception
{
MessageBox.Show("Not a valid date. Please amend");
textBox1.Focus();
return;
}

DateTime today = DateTime.Today;

if (today < dob)
{
MessageBox.Show("User hasn't been born yet! Please amend");
textBox1.Focus();
return;
}

int age;

if(today.Month > dob.Month || (today.Month == dob.Month && today.Day >= dob.Day))
{
age = today.Year - dob.Year;
}
else
{
age = today.Year - dob.Year - 1;
}

if(age >= 135)
{
MessageBox.Show("User can't be as old as this! Please amend");
textBox1.Focus();
return;
}

string message = "Age is " + age;
if (today.Month == dob.Month && today.Day == dob.Day)
{
message += "\r\n\r\nToday's your birthday. Many happy returns!";
}

MessageBox.Show(message);

}