Question

If I have the following Interface structure;

public interface IPaymentTypeBase
{
    void PayNow();
    double Amount { get; set; }
}

public interface IPaymentTypePayPal : IPaymentTypeBase
{
    string UserName { get; set; }
    string Password { get; set; }
}

public interface IPaymentMethod<T>
{
}

Then I have the following classes;

public class PaymentTypePayPal : IPaymentTypePayPal
{
    public string UserName { get; set; }
    public string Password { get; set; }

    public void PayNow()
    {
        throw new NotImplementedException();
    }
}

public class PaymentMethod<T> : IPaymentMethod<T> where T : IPaymentTypeBase
{
}

Then in my web application I have this;

IPaymentMethod<IPaymentTypePayPal> payer = (IPaymentMethod<IPaymentTypePayPal>) new PaymentMethod<PaymentTypePayPal>();

I’d now like to call payer.PayNow(); but I’m just getting lost in interfaces etc and can’t seem to make this work.

I believe this is a simple thing but am just missing the point entierly.

Can anyone help?

Edit

The intention here is to have a set of interface such as PayPal, Voucher, CreditCard all of which do their own payment gateway type of stuff.

So I’d like to instantiate a class that takes the Payment Type as an interface and call that interfaces PayNow method.

Answer 1

payer is of type IPaymentMethod<IPaymentTypePayPal>.

But IPaymentMethod<T> is defined as

public interface IPaymentMethod<T>
{
}

Therefore, it has no methods and you can’t call PayNow() on it.

The same is true for PaymentMethod<T>, so you can’t call any method on an instance of PaymentMethod<PaymentTypePaypal> either.

Maybe you can explain a little more what your intention is.