Question

Lets say I have the following class:

public class Provider
{
    ...
    public sealed class Slice
    {
         public readonly double firstName;
         public readonly double secondName;
         public readonly double thirdName;
         ...
    }
    ...
}

This class is used to hold a sliding time series and the contained Slice class is the return value. (Provider.Last property returns the latest instance of Slice).

I need to get the value of the properties of that latest returned Slice class by name of the property.

PropertyInfo secondNameProperty = Provider.Last.GetType().GetProperty("secondName");
double secondNameValue = (double)secondNameProperty.GetValue(Provider.Last, null);

GetProperty returns null. How can I do this?

Answer 1

Look at your Slice class:

public sealed class Slice
{
     public readonly double firstName;
     public readonly double secondName;
     public readonly double thirdName;
     ...
}

Those aren’t properties. They’re fields. Either make them properties, or use Type.GetField() instead. Using properties would generally be a better idea, IMO, and needn’t be hard. For example, if you just wanted to make them publicly read-only, you could use:

public sealed class Slice
{
     public double FirstName { get; private set; }
     public double SecondName { get; private set; }
     public double ThirdName { get; private set; }
     ...
}

Alternatively you could declare read-only fields directly, and then expose them via properties. It’s a bit more work than using automatically implemented properties, but it removes the potential for setting the property within Slice itself.

(As an aside, do you really have a firstName field of type double? Odd.)