C# Automatically assign property based on other property values

Question

If I have some types e.g:

public class SomeType //Generated by some codegen i won't to change that. {     string C { get; set; }         }  public class AnotherType : SomeType {     string A { get; set; }     string B { get; set; } } 

Is it possible to assign property C automatically? For example when properties A and B get assigned or when I am Casting this type to some another type, or somehow else?

Basically for example I want to execute some logic to automatically assign property C according to values A and B at some point when properties values A and B get populated.

Is there any another ways of doing that rather than using standard properties?

I was thinking that it is possible to do some king of magic when i may cast type AnotherType to SomeType, but i cant implement implicit operator where i may put this conversion logic "from A+B to C" because compiler doesn't allow implicit operator for related types.

Now Only way i see it is remove inheritance and implement implicit operator for AnotherType to SomeType conversion, but the evil in that case i need to duplicate all properties of type SomeType within type AnotherType and i need to change type AnotherType manually every time when SomeType getting changed.

Answer 1

This is possible using auto-implemented properties. You could use the setter of B to assign a value to C:

public class SomeType {     public string A { get; set; }     public string C { get; set; }      private string _b;     public string B      {          get { return _b; }          set          {              // Set B to some new value             _b = value;               // Assign C             C = string.Format("B has been set to {0}", value);         }     } } 

Answer 2

Do you want to be able to set C, or just get it? If you don't need to be able to set the value, then I think you want this:

public class MyClass {     private string _a = "not set";     private string _b = "not set";      public string A     {         get { return _a; }         set { _a = value; }     }      public string B     {         get { return _b; }         set { _b = value; }     }      public string C     {         get         {             if (_a != "not set" && _b != "not set")                 return "not set";             else                 return "set";         }     } } 

Here's a simpler example of accessing a property that is dependent on another property:

public class MyClass {     private double[] MyArray = new double[5];      public int NumElements     {         get         {             return MyArray.Length;         }     } }