Interface vs Struct

[SoAzAppDever]

I am new to object oriented design. I am using VS 2005. I was going to
create three classes then have those classes inherited by one class but c#
does not support multiple inheritance. My three base classes would have
properties only and no methods. What would be best to use in this case an
interface or struct or something else?

When adding items to the project I did not see a template for struct or for
an interface, but there is a template for class (.cs).

Originally I had planned to have three base classes:
Owner class, Property Class and Value Class

And a PropertyHistory class that would inherit all the base classes and
PropertyHistory could be added to a collection so I could iterate through it
and sort it.

I wanted the base classes to be reused separately in other areas of the
application.

What is the best way to do this?

 

[Arne Vajhøj]

I am new to object oriented design. I am using VS 2005. I was going to
create three classes then have those classes inherited by one class but c#
does not support multiple inheritance. My three base classes would have
properties only and no methods. What would be best to use in this case an
interface or struct or something else?

Neither interface or struct solves that problem.

I think you need to make the one class have a reference to the
3 "base" classes instead of inheriting.

Arne

 

[SoAzAppDever]

So In the PropertyHistory class I could pass in the three base classes like so

class PropertyHistory(Owner oObj, Property oProp, Value oVal)
{
do stuff
}

?

 

[Arved Sandstrom]

So In the PropertyHistory class I could pass in the three base classes
like so

class PropertyHistory(Owner oObj, Property oProp, Value oVal)
{
do stuff
}

?

Arne means that since PropertyHistory is not a Property, nor is it a Owner,
nor is it a Value, it won't inherit from any of them. An instance of
PropertyHistory will have references to an instance of Property, an instance
of Owner, and an instance of Value.

AHS

 

[SoAzAppDever]

I am not sure I understand. Can you show me in code? What is have done is
the following:

public class ParcelHistory
{
//members
private Owner _owner;
private Property _property;
private Value _value;


//contructor
public PropertyHistory(Owner owner, Property property, Value value)
{
_owner = owner;
_property = property;
_value = value;
}

//properties
public Owner HistoryOwner
{
get { return _owner; }
}

public Property HistoryProperty
{
get { return _property; }
}

public Value HistoryValue
{
get { return _value; }
}

}

 

[Arne Vajhøj]

Arne means that since PropertyHistory is not a Property, nor is it a Owner,
nor is it a Value, it won't inherit from any of them. An instance of
PropertyHistory will have references to an instance of Property, an instance
of Owner, and an instance of Value.

Yup.

3 x "has a" instead of the invalid 3 x "is a".

Arne

 

[Jeff Louie]

As Arne suggest..

Inheritance represents an IS_A relationship from a generalization to a
specialization. Containment represents a HAS_A relationship between the
whole and a part. So a car IS_A motorized vehicle, but HAS_A radio. The
two
relationships can be expressed in code (text view) thusly:

class Radio
{
...
}
class Vehicle
{
...
}
class Car : Vehicle
{
Radio r= new Radio();
}

Regards,
Jeff

 

[SoAzAppDever]

Thank you that is very helpful!