Formula in C#.net

You can use MathTree lib in MEEL

IExpression expression = BaseExpression.Parse("x/(95+y)");
IExpression result = expression.Execute();

Yeah, there has been a change in the way COM libraries work in VS 2010.

Previously, COM methods which returned a Variant, returned this to C# code as an 'object'. You then had to cast it back to the exact underlying type or you'd get an exception.

VS 2010 (C# 4.0) now uses the 'dynamic' type in this scenario which is more forgiving than 'object'. Basically, if the conversion is valid at runtime, then it's allowed regardless of the underlying type. In fact you don't even need a cast any more. This line works fine in VS 2010:

  double c = sc.Eval(formula); // no cast needed!

Thanks Vulpes for ur reply. 
Your solutions has solved the problem

I am using VS 2005.

I just tried using double instead of int myself but it worked fine.

Are you using VS 2010 and v1.0 of the ScriptControl?

What you're trying to do is not possible because methods such as int.Parse, double.Parse etc, do not recognize arithmetic operators such as *, +, - and /.

If you're trying to do this for arbitrarily complex formulae, then you need to use an Eval() function such as the one provided by VBScript which can be used from C#.

To do this, start a new console application project in VS and add a reference to the Microsoft Script Control 1.0 which can be found under the COM tab.

Now enter the following code, build and run:

using System.Text;
using MSScriptControl;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            var sc = new ScriptControl();
            sc.Language = "VBScript";
            string formula = "a*b";
            int a = 10;
            int b = 10;
            formula = formula.Replace("a", a.ToString());
            formula = formula.Replace("b", b.ToString());
            int c = (int)sc.Eval(formula);
            Console.WriteLine("Result: " + c);
            Console.ReadKey();
        }
    }
}

Actually i cant set Formula as integer.
Because i am keeping formula in formula master table.
In formula master, i have used 2 fields:1)Formula_Name & 2) Formula_String
EG:
Formula MAster Table:
FormulaName  Formula_String
SquareArea     Width*Width
RectangleArea  Width*Length

try this:
            int a = 10;
            int b = 20;
            int x = a * b;
            string y = Convert.ToString(x);
            int z = Convert.ToInt32(y);

Jitendra,

I have tried ur code. bt it is not solving my issues.

try this:

            string y = "result is" + a * b+ "Hope this help you";

Hi Jitendra
Actually iam trying to fix formula in string & then calculating values using that formula.

Is it possible?
Eg:

Hi pravin,

            int a = 10;
            int b = 20;
            int x = a * b;
            Console.WriteLine("Result:" + x);