IWorksheetFunction - problem with object reference-CodePudding

i use Microsoft.Office.Interop.Excel

and i have error in my code with it

an object reference is required for the non-static field method or property

 public class CalculationsController : Controller
  {
 public double Irr(double a, double b)
    {

      Irr irr = new Irr()
      {
        a = a,
        b = b
      };

      var y = IWorksheetFunction.Irr(irr.a, irr.b); // here error

      return y;

    }

public class Irr
  {
    public double a { get; set; }
    public double b { get; set; }
  }
}

i cant do change in IWorksheetFunction.Irr, beacause its package

CodePudding user response：

The first problem with your code as highlighted by @Fildor in the comments. You can't make calls to an Interface. You should view Interfaces as blueprints. You should be calling the WorksheetFunction class instead since this implements the IWorksheetFunction Interface.

The second possible issue is that you haven't included the right library to access the WorksheetFunction class. You can include it by placing this at the very top of the file.

using Microsoft.Office.Interop.Excel;

If this gives any issue you might need to install the Microsoft.Office.Interop.Excel nuget package. Here is how you can do that