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What I'm trying to do is have a class that I can inherit from and be able to track changes to properties.

I have this base class called TrackedEntity.

I then create another class TestEntity that inherits from TrackedEntity.

On my TestEntity class I have marked one of my fields with an attribute that I called CompareValues.

TrackedEntity 

  public class TrackedEntity {
        public void GetCompareValues<T> () {

            var type = typeof (T);
            var properties = type.GetProperties ();

            foreach (var property in properties) {

              var attribute = (CompareValues[]) property.GetCustomAttributes 
                                             (typeof(CompareValues), false);

              var hasAttribute = Attribute.IsDefined (property, typeof 
                                   (CompareValues));

            }
        }
    }

TestEntity

public class TestEntity : TrackedEntity
    {
        public int one { get; set; }
        [CompareValues]
        public int two { get; set; }
        public int three { get; set; }
    }

CompareValues attribute:

 [AttributeUsage ( AttributeTargets.Property | 
                      AttributeTargets.Field,
                      Inherited = true)]
    public class CompareValues : Attribute {
        public CompareValues () { }
    }

I can then do this

var test  = new TestEntity ();
test.GetCompareValues<TestEntity> ();

In my GetCompareValues method I can find which fields in TestEntity use my CompareValues attribute.

I am trying to find a way to access the value of the fields that have the CompareValues attribute so that I can track the changes and log information about it.

If there is any other way to get this done by using another method please let me know.

Thank you.

The Riccardo
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    `GetType()` returns the actual runtime type of the object, even when you call it on a reference to a base class. There would be little point in it otherwise. – 15ee8f99-57ff-4f92-890c-b56153 Aug 21 '19 at 12:52
  • Your question isn't written very clearly. Your title says you want to get fields, but the code you posted involves properties. Regardless, getting the fields or properties of a specific object is a well-known, well-documented operation, and questions related to that have been answered literally hundreds of times on Stack Overflow. See marked duplicates for examples. – Peter Duniho Aug 21 '19 at 16:19
  • Sorry about that! – The Riccardo Aug 22 '19 at 08:59

1 Answers1

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You´re almost there. All you need to do is to get the properties value on the current instance - the instance on which you´ve called the method:

if(hasAttribute)
{
    var value = property.GetValue(this, null);
}

Apart from this you won´t need generics here. Just use this:

var type = this.GetType();

which returns TestEntity in case of the instance being of your derived type.

MakePeaceGreatAgain
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