Unity Custom Editor NullReferenceException When SerializedProperty Has Any Accessor

Question

I am trying to make a custom editor in Unity for a ScriptableObject class which has private fields like such:

But has soon as one of my fields has an accessor (I also tried properties with get;), I get the following error when I try to see my ScriptableObject in the inspector.

I made some tests and it works perfectly without accessors. For instance, I can see the field "test". Here is the code for my custom editor:

Any idea? I would not believe a custom editor for a class that has accessors would not be supported. Thank you!

Answer 1

This has nothing to do with an "accessor". And note that properties are not serialized by Unity at all.

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The mistake is pretty simple: Your field's name is not ingredients but rather _ingredients!

Therefore FindProperty("ingredients") returns null since it doesn't find any field called ingredients.

(This is assuming of course that Item is a [Serializable] type at all.)

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To avoid exactly this type of issues I usually prefer to embed the editor into the type itself and use e.g.

public class YourType : MonoBehaviour /*or ScriptableObject*/
{
    [SerializeField] private int _someField;

#if UNITY_EDITOR
    [CustomEditor(typeof(YourType))]
    private class YourTypeEditor : Editor
    {
        private SerializedProperty _someFieldProperty;

        private void OnEnable()
        {
            _someFieldProperty = serializedObject.FindProperty(nameof(_someField));
        }

        ...
    }
#endif
}

so whenever you rename the fields it will be fixed in the Inspector automatically