Is there a better way to determine if a string can be an integer other than try/catch?

Question

I needed a function that simply checks if a string can be converted to a valid integer (for form validation).

After searching around, I ended up using a function I had from 2002 which works using C#1 (below).

However, it just seems to me that although the code below works, it is a misuse of try/catch to use it not to catch an error but to determine a value.

Is there a better way to do this in C#3?

public static bool IsAValidInteger(string strWholeNumber)
{
    try
    {
        int wholeNumber = Convert.ToInt32(strWholeNumber);
        return true;
    }
    catch
    {
        return false;
    }
}

Answer:

John's answer below helped me build the function I was after without the try/catch. In this case, a blank textbox is also considered a valid "whole number" in my form:

public static bool IsAValidWholeNumber(string questionalWholeNumber)
{
    int result;

    if (questionalWholeNumber.Trim() == "" || int.TryParse(questionalWholeNumber, out result))
    {
        return true;
    }
    else
    {
        return false;
    }
}

Answer 1

Int32.TryParse

Answer 2

if (int.TryParse(string, out result))
{
    // use result here
}

Answer 3

This probably won't be much faster, but at least it looks cleaner (no exception handling):

 public static bool IsAValidInteger(string strWholeNumber)
 {
     int wholeNumber;
     return int.TryParse(strWholeNumber, out wholeNumber);
 }

Answer 4

You are looking for Int32.TryParse().

public void Foo(String input)
{
    Int32 number;
    if (Int32.TryParse(input, out number))
    {
        DoStuff(number);
    }
    else
    {
        HandleInvalidInput(input);
    }
}

In your specific case I would use the following.

public static Boolean IsValidInt32(String input)
{
    Int32 number;
    return Int32.TryParse(input, out number);
}

Answer 5

The try/catch approach is a valid solution because for many types there are not TryParse methods implemented. So you revert to the basically one option left.