C# substituer les fonctions virtuelles sans avoir à mettre en place une autre classe - Stack Overflow

I am trying to override a virtual function only for a single defined element (without having to create another class that implements it and then adding a function to override it..).

Example:

public class MyClass
{
    public virtual bool ChangeStatus(String status)
    {
        return false;
    }
}


void test()
{
    //The following is written as an example of what I am trying to achieve & does not work
    MyClass blah = new MyClass()
    {
        public override bool ChangeStatus(String status)
        {
            return true;
        }
    };
}

Any idea how to achieve this?

Thanks.

if you have control over MyClass, you can let the desired method call a delegate which can be replaced for every single object at runtime...

class MyClass
{
    public void Func<SomeParameterType,SomeReturnType> myDelegate {get;set;}
    public SomeReturnType myFunction(SomeParameterType parameter)
    {
        if(myDelegate==null)
            throw new Exception();
        return myDelegate(parameter);
    }
}

...

MyClass obj = new MyClass();
SomeParameterType p = new SomeParameterType();
obj.myDelegate = (x)=>new SomeReturnType(x);
SomeReturnType result = obj.myFunction(p);

"virtual" and "override" both are related to INHERITANCE.

1.A virtual method can be redefined. The virtual keyword designates a method that is overridden in derived classes. We can add derived types without modifying the rest of the program. The runtime type of objects thus determines behavior.

2.When you want to allow a derived class to override a method of the base class, within the base class method must be created as virtual method and within the derived class method must be created using the keyword override.

You cannot override a function without inheriting the class, the whole point of a virtual function is that it can be overridden in the child class.

If your are doing it withing the same class, wouldn't you end up writing a simple method/function for the class ?

So, follow the OOP programming concept, it is designed for simplicity & ease of programming. Instead simply inherit the class and override the function

C# is strictly built on the concept of classes. You cannot create a function/method without a class.
Additionally, virtual/override implies inheritance, so you MUST derive from this class.

I am trying to override a virtual function only for a single defined element (without having to create another class that implements it and then adding a function to override it..).

Example:

public class MyClass
{
    public virtual bool ChangeStatus(String status)
    {
        return false;
    }
}


void test()
{
    //The following is written as an example of what I am trying to achieve & does not work
    MyClass blah = new MyClass()
    {
        public override bool ChangeStatus(String status)
        {
            return true;
        }
    };
}

Any idea how to achieve this?

Thanks.

if you have control over MyClass, you can let the desired method call a delegate which can be replaced for every single object at runtime...

class MyClass
{
    public void Func<SomeParameterType,SomeReturnType> myDelegate {get;set;}
    public SomeReturnType myFunction(SomeParameterType parameter)
    {
        if(myDelegate==null)
            throw new Exception();
        return myDelegate(parameter);
    }
}

...

MyClass obj = new MyClass();
SomeParameterType p = new SomeParameterType();
obj.myDelegate = (x)=>new SomeReturnType(x);
SomeReturnType result = obj.myFunction(p);

"virtual" and "override" both are related to INHERITANCE.

1.A virtual method can be redefined. The virtual keyword designates a method that is overridden in derived classes. We can add derived types without modifying the rest of the program. The runtime type of objects thus determines behavior.

2.When you want to allow a derived class to override a method of the base class, within the base class method must be created as virtual method and within the derived class method must be created using the keyword override.

You cannot override a function without inheriting the class, the whole point of a virtual function is that it can be overridden in the child class.

If your are doing it withing the same class, wouldn't you end up writing a simple method/function for the class ?

So, follow the OOP programming concept, it is designed for simplicity & ease of programming. Instead simply inherit the class and override the function

C# is strictly built on the concept of classes. You cannot create a function/method without a class.
Additionally, virtual/override implies inheritance, so you MUST derive from this class.

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