2接口（i1，i2），2个抽象类（A：i1，B：i2），一个类（摘要：i1，i2）。 如何访问抽象类的所有方法

Question

I have two abstract Class IExcelHelper and ICoreExcelHelper inherit by ExcelHelper and CoreExcelHelper. I have one class that inherits two interfaces: IExcelHelper & ICoreExcelHelper. I want to access all method of abstract class whether methods are not implemented. Here I am unable to access the Test Method of ExcelHelper.

any suggestion?

public interface IExcelHelper
{
    void GenerateReport();
}
public interface ICoreExcelHelper
{
    void GenerateReport();
}

public abstract class ExcelHelper : IExcelHelper
{
    public abstract void GenerateReport();

    public void Test()
    {
        Console.WriteLine("Test");
    }
}

public abstract class CoreExcelHelper : ICoreExcelHelper
{
    public abstract void GenerateReport();
}

public class GenerateExcelStrategySummary : IExcelHelper, ICoreExcelHelper
{
    void IExcelHelper.GenerateReport()
    {
        Console.WriteLine("GenerateReport");
    }

    void ICoreExcelHelper.GenerateReport()
    {
        Console.WriteLine("CoreGenerateReport");
    }
}

class Program
{
    static void Main(string[] args)
    {
        IExcelHelper obj = new GenerateExcelStrategySummary();
        obj.GenerateReport();

        obj.Test();

        ICoreExcelHelper obj1 = new GenerateExcelStrategySummary();
        obj1.GenerateReport();

        Console.WriteLine("Hello World!");
        Console.ReadLine();
    }
}

Answer 1

I would argue that you don't really gain anything by having the same definition in two different interfaces and that casting interfaces to concrete types is not a good approach. Both definitions in IExcelHelper and ICoreExcelHelper will do the same fundamental thing which is generate a report but in a different way. I would define one report interface and have the strategy object return an instance or take an instance as a dependency. The power of using interfaces is being able to code to a behavior rather than a concrete type.

public interface IGenerateReport {
  void GenerateReport();
  void Test();
}

public abstract class HelperBase : IGenerateReport {

  public abstract void GenerateReport();

  public void Test() {
    Console.WriteLine("Test");
  }

}

public class ExcelHelper : HelperBase {

  public override void GenerateReport() 
  {
    //I generate my report this way
  }

}

public class CoreHelper : HelperBase {

  public override void GenerateReport() 
  {
    //I will generate my report in a totally different way
  }

}

This will allow you to define your types as either HelperBase or IGenerateReport and you will have access to all your methods.

IGenerateReport helper = new ExcelHelper();
helper.Test();
helper.GenerateReport();

helper = new CoreHelper();
helper.Test();
helper.GenerateReport();

HelperBase helper2 = new ExcelHelper();
helper2.Test();
helper2.GenerateReport();