Setting a ref to a member field in C#

Question

I\'d like to assign a reference to a member field. But I obviously do not understand this part of C# very well, because I failed :-) So, here\'s my code:

public          


        

Answer 1

If you don't want to introduce another class like MyRef or StringBuilder because your string is already a property in an existing class you can use a Func and Action to achieve the result you are looking for.

public class End {
    private readonly Func getter;
    private readonly Action setter;

    public End(Func getter, Action setter) {
        this.getter = getter;
        this.setter = setter;
        this.Init();
        Console.WriteLine("Inside: {0}", getter());
    }

    public void Init() {
        setter("success");
    }
}

class MainClass 
{
    public static void Main(string[] args) 
    {
        string s = "failed";
        End e = new End(() => s, (x) => {s = x; });
        Console.WriteLine("After: {0}", s);
    }
}

And if you want to simplify the calling side further (at the expense of some run-time) you can use a method like the one below to turn (some) getters into setters.

    /// 

    /// Convert a lambda expression for a getter into a setter
    /// 
    public static Action GetSetter(Expression> expression)
    {
        var memberExpression = (MemberExpression)expression.Body;
        var property = (PropertyInfo)memberExpression.Member;
        var setMethod = property.GetSetMethod();

        var parameterT = Expression.Parameter(typeof(T), "x");
        var parameterU = Expression.Parameter(typeof(U), "y");

        var newExpression =
            Expression.Lambda>(
                Expression.Call(parameterT, setMethod, parameterU),
                parameterT,
                parameterU
            );

        return newExpression.Compile();
    }