CustomPropertyDrawer for My Custom Generic Type

Unity Engine
1

I have this code:

[System.Serializable]
        public class ExclusiveList<T> : List<T>
        {
            public int this[T item]
            {
                get
                {
                    for(int i = 0; i < Count; i++)
                    {
                        if(this[i].Equals(item))
                        {
                            return i;
                        }
                    }
                    return -1;
                }
            }
            new public void Add(T item)
            {
                if (!Contains(item))
                {
                    base.Add(item);
                }
            }
          
        }
        [CustomPropertyDrawer(typeof(ExclusiveList<>),true)]
        public class ExclusiveListPropertyDrawer<T> : PropertyDrawer where T:Object
        {
            private int length;
            public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
            {
                EditorGUI.BeginProperty(position,label,property);

                ExclusiveList<T> xList = property.FindPropertyRelative("this") as ExclusiveList<T>;
                length = EditorGUI.IntField(position,length);
                for (int i = 0; i < xList.Count; i++)
                {
                   
                    if(xList[xList[i]] != -1)
                    {
                        xList.RemoveAt(i);
                        i--;
                    }
                    xList[i] = (T)EditorGUI.ObjectField(position,xList[i],typeof(T),true);
                }

                EditorGUI.EndProperty();
            }
        }

But it does not work.How can I solve this ? Thanks in advance!

2

It does not work! How about that.

How to report your problem productively in the Unity3D forums:

http://plbm.com/?p=220

How to understand compiler and other errors and even fix them yourself:

https://discussions.unity.com/t/824586/8

If you post a code snippet, ALWAYS USE CODE TAGS:

How to use code tags: https://discussions.unity.com/t/481379

Use code tags:
https://www.youtube.com/watch?v=84kaypWK1bM

What is often happening in these cases is one of the following:

  • the code you think is executing is not actually executing at all
  • the code is executing far EARLIER or LATER than you think
  • the code is executing far LESS OFTEN than you think
  • the code is executing far MORE OFTEN than you think
  • the code is executing on another GameObject than you think it is

To help gain more insight into your problem, I recommend liberally sprinkling Debug.Log() statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

  • is this code even running? which parts are running? how often does it run? what order does it run in?
  • what are the values of the variables involved? Are they initialized? Are the values reasonable?
  • are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

Knowing this information will help you reason about the behavior you are seeing.

You can also put in Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene

You could also just display various important quantities in UI Text elements to watch them change as you play the game.

If you are running a mobile device you can also view the console output. Google for how on your particular mobile target.

Here’s an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong:

https://discussions.unity.com/t/839300/3