Validation in C#

Question

I having a textbox which user need to enter customer number(ex : 123456789). what is my issue is if they enter (ex:000000000 or 000 or,0000,or 00000) I need to valid as it is ID Should not be zero invalid . how I need to do in C# code behind .

Answer 1

I need to valid as it is ID Should not be zero invalid

If this is the only rule (I can't say like it), you can try to parse your string (which is probably you get this from user) with Int32.TryParse method and then check your integer is bigger than 0 or not. Like;

string input;
int number;
if (Int32.TryParse(input, out number))
{
   if(number > 0)
   {
       // Your input can be parsed to int and it is greater than zero.
   }        
}

Remember, don't check your number is 0 or not. Because if your string couldn't parse with Int32.TryParse method, your number will be 0 by default.

result Type: System.Int32

When this method returns, contains the 32-bit signed integer value equivalent of the number contained in s, if the conversion succeeded, or zero if the conversion failed.