C# CurveOffsetOnSrf

Hello Guys,

I am starting to learn C#, I have a bit of a problem, I am trying use the 

Crv.OffsetOnSurface

But it seam that in some occasions it throws a null Crv, I can fix this just by multiplying the Distance Value by -1, but i would like to run an internal test using conditional but I can figure out how to do it. I try Both methods but no result...

Any help would be greatly appreciated!

Best!

private void RunScript(Surface Srf, Curve Crv, double Dis, double Tolerance, ref object A){

Curve[] Crv1;
Curve[] Crv2;

Crv1 = Crv.OffsetOnSurface(Srf, Dis * -1, Tolerance);
Crv1.Count;

if ( Crv1.Count == 0) {
Crv2 = Crv.OffsetOnSurface(Srf, Dis, Tolerance);
} else {
Crv2 = Crv.OffsetOnSurface(Srf, Dis * -1, Tolerance);
}

A = Crv2;

}

"OR"

private void RunScript(Surface Srf, Curve Crv, double Dis, double Tolerance, ref object A){

Curve[] Crv1;
Curve[] Crv2;

Crv1 = Crv.OffsetOnSurface(Srf, Dis * -1, Tolerance);

if ( Crv1 == null) {
Crv2 = Crv.OffsetOnSurface(Srf, Dis, Tolerance);
} else {
Crv2 = Crv.OffsetOnSurface(Srf, Dis * -1, Tolerance);
}

A = Crv2;

}