Passing model class as a generic type parameter

Question

I have a skeleton code like this. I want to create a method that can take a generic model as its argument. Inside GenericMethod, if I wanted to access the property of models, how do I actually configure the method?

public class ModelA
{
    public string Name { get; set;}
    public int Property1 { get; set; }
}

public class ModelB
{
    public string Name { get; set;}
    public int Property2 { get; set; }
}

public class MainClass
{
    public async Task<int> ProcessA()
    {
        await GenericMethod(ModelA modelA);
    }

    public async Task<int> ProcessB()
    {
        await GenericMethod(ModelB modelB);
    }

    public async Task<int> GenericMethod<T>(T model) where T : something?
    {
        // Get model name here like this
         model.Name
    }
}

Any help would be highly appreciated. Thank you.

Answer 1

I would use a common interface for this, for example IHaveName :

public interface IHaveName
{
    string Name { get;set; }
}


public class ModelA: IHaveName
{
    public string Name { get; set; }
}

public class ModelB: IHaveName
{
    public string Name { get; set; }
}

Now you can make a constraint on it:

public async Task<int> GenericMethod<T>(T model) where T : IHaveName
{
    // Get model name here like this
     model.Name
}

Interfaces are better than classes here since you can implement multiple and they have other advantages(for example unit tests, IoC etc.).

Answer 2

inherit ModelA and ModelB from a common parent having the field Name, and make like

public async Task<int> GenericMethod<T>(T model) where T : IModelParent

Answer 3

You can make a parent class for your models and pass its type as an argument.

abstract class ModelParent
{
    public virtual string Name { get; set; }
}

public class ModelA : ModelParent
{
    public override string Name { get => base.Name; set => base.Name = value; }
}

public class ModelB : ModelParent
{
    public override string Name { get => base.Name; set => base.Name = value; }
}

public class MainClass
{
    public async Task<int> ProcessA()
    {
        await GenericMethod(ModelA modelA);
    }

    public async Task<int> ProcessB()
    {
        await GenericMethod(ModelB modelB);
    }

    public async Task<int> GenericMethod<T>(T model) where T : ModelParent
    {
        // Get model name here like this
        model.Name
    }
}

Assuming that you do not need/want any instances of Parent class, you might want to make it an abstract.

Some links

• https://docs.microsoft.com/en-us/dotnet/csharp/tutorials/inheritance
• https://www.tutorialspoint.com/csharp/csharp_inheritance.htm

to read: