Changing read only properties with reflection

by

As other stated, if you need to do that, you’re facing a design issue to begin with. Now, if you want to know if it’s possible just for the sake of knowing, or if there’s no other way on earth to do it, it’s indeed possible, with the help of a very small helper library and an extension method.

Consider the following code:

class Person {

    int age;
    string name;

    public int Age { get { return age; } }
    public string Name { get { return name; } }
}

// ...

using Mono.Reflection;
using System.Reflection;

// ...

Person person = new Person (27, "jb");
PropertyInfo nameProperty = typeof (Person).GetProperty ("Name");
FieldInfo nameField = nameProperty.GetBackingField ();
nameField.SetValue (person, "jbe");

Using this code, you can get the backing field of a property with just the property, and assign a new value to the backing field. You can read more details about the implementation.

Also note that it works only for simple properties, such as:

public int Age { get { return age; } }

public string Name {
    get { return name; }
    set { name = value; }
}

public double Velocity { get; private set; }

If you have complex properties with custom code (which includes expression-bodied member like int Answer=> 42;), the backing field resolver will fail as there is no backing field in such case.

More Related Contents:

  1. Get property value from string using reflection
  2. Check if a class is derived from a generic class
  3. Loading DLLs at runtime in C#
  4. How do I intercept a method call in C#?
  5. Getting the size of a field in bytes with C#
  6. Testing if object is of generic type in C#
  7. How can I get all constants of a type by reflection?
  8. How do I invoke an extension method using reflection?
  9. How does WCF deserialization instantiate objects without calling a constructor?
  10. How to use reflection to call method by name
  11. Get property name and type using lambda expression
  12. How to call generic method with a given Type object? [duplicate]
  13. How do I get the member to which my custom attribute was applied?
  14. Getting a System.Type from type’s partial name
  15. How to get a property value using reflection
  16. How To Test if a Type is Anonymous? [duplicate]
  17. How to find all the classes which implement a given interface?
  18. How to load Assembly at runtime and create class instance?
  19. Programmatically get Summary comments at runtime
  20. Finding out if a type implements a generic interface
  21. C#: how to get an object by the name stored in String?
  22. C# instantiate generic List from reflected Type [duplicate]
  23. How to pass a parameter as a reference with MethodInfo.Invoke
  24. How to get current property name via reflection?
  25. Dynamically creating a proxy class
  26. How do I invoke a static constructor with reflection?
  27. Using Reflection to create a DataTable from a Class?
  28. Is there any way to get a reference to the calling object in c#?
  29. Get private Properties/Method of base-class with reflection
  30. Reflection Performance – Create Delegate (Properties C#)

Leave a Comment