Issue with system.reflection, GetFields not returning everything

Question

Im having a bit of an issue with System.Reflection. Please see the attached code:

class Program
{
    public static FieldInfo[] ReflectionMethod(object obj)
    {
        var flags = BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.DeclaredOnly;
        return obj.GetType().GetFields(flags);
    }
        static void Main()
    {
        var test = new Test() { Id = 0, Age = 12, Height = 24, IsSomething = true, Name = "Greg", Weight = 100 };
        var res = ReflectionMethod(test);
    }
}

    public class Test
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }
    public bool IsSomething { get; set; }
    public int Weight { get; set; }
    public int Height { get; set; }
    public int CalculationResult => Weight * Height;

    public Test()
    {

    }
}

It seems as though the getfields method is not getting the calculated property CalculationResult. I'm assuming there is another flag I need to use, but I can't figure out which one it is.

Thanks in advance and I'll happily provide more info if necessary.

score 4 · Accepted Answer · answered Aug 01 '16 at 17:02

4

That is because it is a property and not a field.

=> is a syntactic sugar for a getter which is a property. So it is equivelant to:

public int CalculationResult 
{ 
   get 
   { 
      return Weight * Height; 
   }
}

So you need to use .GetProperties(flags)

answered Aug 01 '16 at 17:02

Zein Makki

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and thank you for introducing me to the phrase "syntactic sugar", I'm going to use it more in conversation – ASMoncrieff Aug 01 '16 at 17:13

Fabjan · Answer 2 · 2016-08-01T17:09:50.270

Well, analyzing this line of code :

public int CalculationResult => Weight * Height;

Which can also be simplified to (without C# 6.0 syntactic sugar) :

public int CalculationResult {get { return Weight*Height; } }

Compiler doesn't create backing field because it's not auto-property and that's why it is not among the fields retrieved from class by reflection calls.

If you change it to public int CalculationResult { get; } it will create the field and it will show up in the list.

Issue with system.reflection, GetFields not returning everything

2 Answers2