Question

I have this function I have to implement:

protected override ValidationResult IsValid(
    Object value,
    ValidationContext validationContext
)
{
  //Here is where I wanna test whether the following conversion is applicable
  var x = Convert.ToInt64(value);
}

I could wrap that line in a try-catch block, or with other ways to perform that test, here is one of them:

var convertible = value as IConvertible;
if (convertible != null)
  var x = convertible.ToInt64(null);

What’s the most efficient way to do this?

Answer 1

here you can define a default value, if the parse (conversion) is applicable it will return the converted int64 otherwise the default value will be returned:

Int64 DefaultValue = 0;
Int64.TryParse(MyVar , out DefaultValue);

ie:

Int64 DefaultValue = 0;
Int64.TryParse("1234" , out DefaultValue);

DefaultValue will be 1234

Int64 DefaultValue = 0;
 Int64.TryParse("test" , out DefaultValue);

DefaultValue will be 0

You can also make it even shrorter by declaring the variable like this:

 Int64.TryParse("123" , out Int64 DefaultValue);