将属性设置为通用参数

Question

I have two classes Car and Truck , and they both extend my Vehicle class. Both Car and Truck have property that looks like this:

public int Wheels { get; set; }

Now, I have two methods which set the Wheels property to some variable. It looks like this:

public void SetCarWheels(int value)
{
     Car.Wheels = value;
}

public void SetTruckWheels(int value)
{
     Truck.Wheels = value;
}

Because the methods do the same thing, I wanted to make a method which would have an input parameter of type Vehicle . The method should basically do this:

public static void SetWheels<T>(Vehicle item, int wheels) where T : Vehicle
    {
        if (item!= null)
        {
            item.Wheels = wheels;
        }
    }

The problem is, it doesn't recognize the Wheels property.

How can I solve this by using generics?

Please don't suggest alternative solutions without generics (I know that Car and Truck can have a const value of wheels, but for the sake of the problem let's leave this as it is).

Answer 1

Your code will only work if the property is an instance property in the Vehicle base class:

public class Vehicle
{
    public int Wheels { get; set; }
}

Also, in your method you don't seem to use the generic type parameter and the variable:

public static void SetWheels<T>(T item, int wheels) where T : Vehicle
{
    if (item != null)
    {
        item.Wheels = wheels;
    }
}