Should I separate properties and methods in partial classes?

Question

I am writing fundamental classes for an application and want to build them correctly for long-term support. To this end, I will explore which design patterns to implement, use interfaces, abstract classes, and separate persistence from activity. My head swims with patterns, paradigms and principles.

I have a class Productfor which I created an interface IProduct. I believe that I need to make an Productabstract class, because any instance of it should be one of half a dozen values ​​for the property Category. So my first question is: the next way to do this?

abstract class Product : IProduct
{
    // Fields
    // Properties
    // Methods
}

interface IProduct
{
    // Properties
}

public class Model : IProduct
{
    public Model()
    {
        Category = "Model";
    }

    // Model-specific fields
    // Model-specific properties
    // Model-specific methods
}

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abstract class Product : IProduct
{
    // Fields
    // Properties
    // Methods
}

interface IProduct
{
    // Properties
}

public partial class Model : IProduct
{
    public Model()
    {
        Category = "Model";
    }

    // Model-specific fields
    // Model-specific properties
}

public partial class Model : IProduct
{
    // Model-specific methods
}

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abstract class Product : IProduct
{
    // Fields
    // Properties
}
abstract class Product : IProduct
{
    // Methods
}

Answer 1

, partial, - , . , , Visual Studio (, Windows Forms), . . , .

partial, . #region .

Answer 2

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#region . , (------…---), .

:

public class SomeClass : ParentClass, ISomeInterface
{
    #region ------ Large feature 1 ----------------------------
    … // any non-private members related to 'Large feature 1' go here
    #endregion

    #region ------ Large feature 2 ----------------------------
    … // any non-private members related to 'Large feature 2' go here
    #endregion

    #region ------ Implementation of ISomeInterface -----------
    … // ISomeInterface implementation goes here, comments are *not* repeated
    #endregion

    #region ------ ParentClass overrides ----------------------
    … // parent class members' overrides go here, comments are *not* repeated
    #endregion

    #region ------ Internals ----------------------------------
    … // any private members, i.e. the actual implementation
    #endregion
}

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public int SomeProperty
{
    get { … return someProperty; }
    set { someProperty = value; … }
}
private int someProperty;