C# – inherit constructors

cdry

I know it's not possible to inherit constructors in C#, but there's probably a way to do what I want to do.

I have a base class that is inherited by many other classes, and it has an Init method that does some initializing taking 1 parameter. All other inheriting classes also need this initializing, but I'd need to create separate constructors for all of them that would like like this:

public Constructor(Parameter p) {
    base.Init(p);
}

That totally violates the DRY principles! How can I have all necessary stuff initialized without creating dozens of constructors?

Best Answer

You don't need to create loads of constructors, all with the same code; you create only one, but have the derived classes call the base constructor:

public class Base
{
    public Base(Parameter p)
    {
        Init(p)
    }

    void Init(Parameter p)
    {
        // common initialisation code
    }
}

public class Derived : Base
{
    public Derived(Parameter p) : base(p)
    {
 
    }
}

Related Solutions

C# – How to cast int to enum

From an int:

YourEnum foo = (YourEnum)yourInt;

From a string:

YourEnum foo = (YourEnum) Enum.Parse(typeof(YourEnum), yourString);

// The foo.ToString().Contains(",") check is necessary for enumerations marked with an [Flags] attribute
if (!Enum.IsDefined(typeof(YourEnum), foo) && !foo.ToString().Contains(","))
{
    throw new InvalidOperationException($"{yourString} is not an underlying value of the YourEnum enumeration.")
}

Update:

From number you can also

YourEnum foo = (YourEnum)Enum.ToObject(typeof(YourEnum) , yourInt);

C# – Order of items in classes: Fields, Properties, Constructors, Methods

According to the StyleCop Rules Documentation the ordering is as follows.

Within a class, struct or interface: (SA1201 and SA1203)

Constant Fields
Fields
Constructors
Finalizers (Destructors)
Delegates
Events
Enums
Interfaces (interface implementations)
Properties
Indexers
Methods
Structs
Classes

Within each of these groups order by access: (SA1202)

public
internal
protected internal
protected
private

Within each of the access groups, order by static, then non-static: (SA1204)

static
non-static

Within each of the static/non-static groups of fields, order by readonly, then non-readonly : (SA1214 and SA1215)

readonly
non-readonly

An unrolled list is 130 lines long, so I won't unroll it here. The methods part unrolled is:

public static methods
public methods
internal static methods
internal methods
protected internal static methods
protected internal methods
protected static methods
protected methods
private static methods
private methods

The documentation notes that if the prescribed order isn't suitable - say, multiple interfaces are being implemented, and the interface methods and properties should be grouped together - then use a partial class to group the related methods and properties together.

Best Answer

Related Solutions

C# – How to cast int to enum

C# – Order of items in classes: Fields, Properties, Constructors, Methods

Related Topic