我可以创建自定义 MonoBehaviour 编辑器来编辑 ScriptableObject 字段中的列表吗？

Question

I have a custom editor for a MonoBehaviour to display a reorderable list of items.

public class MyComponent : MonoBehaviour
{
   public MyArrayElement[] myList;
}

public struct MyArrayElement
{
   public string firstField;
   public string secondField;  
}

[CustomEditor(typeof(MyComponent))]
public class MyComponentEditor : Editor
{
    private ReorderableList list;

    private void OnEnable()
    {
        SerializedProperty property = this.serializedObject.FindProperty("myList");
        this.list = new ReorderableList(this.serializedObject, property, true, true, true, true);
        list.drawElementCallback = DrawListItems;
    }

    public override void OnInspectorGUI()
    {
        serializedObject.Update();
        list.DoLayoutList();
        serializedObject.ApplyModifiedProperties();
    }

    void DrawListItems(Rect rect, int index, bool isActive, bool isFocused)
    {
        EditorGUI.PropertyField(
           new Rect(rect.x, rect.y, 100, EditorGUIUtility.singleLineHeight), 
           element.FindPropertyRelative("firstField"), 
           GUIContent.none);

        EditorGUI.PropertyField(
           new Rect(rect.x + 150, rect.y, 100, EditorGUIUtility.singleLineHeight), 
           element.FindPropertyRelative("secondField"), 
           GUIContent.none);
    }
}

This works correctly. However, I would like to have the Inspector for every instance of this MonoBehaviour edit the same set of elements, so I created a ScriptableObject

public MyScriptableObject : ScriptableObject
{
   public MyArrayElement[] myList;  
}

And then replace MyComponent.myList with an instance of MyScriptableObject

public class MyComponent : MonoBehaviour
{       
   // Remove this
   // public MyArrayElement[] myList;

   // Add this
   public MyScriptableObject myScriptableObject;
}

Then I want to update my custom editor for the MonoBehaviour to show myScriptableObject.myList

I tried this, but the list is empty in the Inspector, even if the ScriptableObject 's list is not empty

SerializedProperty property = this.serializedObject.FindProperty("myScriptableObject").FindPropertyRelative("myList");
this.list = new ReorderableList(this.serializedObject, property, true, true, true, true);

Is there a way to get my MonoBehaviour s editor to let me edit the ScriptableObject s array?

Answer 1

Yes there is; ;)

But first of all: Starting with Unity 2020 there is no need to use ReorderableList anymore except you want some very special behavior which seems not to be the case here. For List<T> and T[] this is now the default drawer anyway!

And then using FindPropertyRelative only works for [Serializable] classes.

Whenever you deal with a separate UnityEngine.Object what you need to do is go through the SerializedObject of the instance of that reference.

Like eg

var property = serializedObject.FindProperty("myScriptableObject").FindPropertyRelative("myList");
EditorGUILayout.PropertyField(property, true);

if(property.objectReferenceValue)
{
    var so = new SerializedObject(property.objectReferenceValue);
    so.Update();
    
    var list = so.FindProperty("myList");

    EditorGUILayout.PropertyField(list, true);

    so.ApplyModifiedProperties();
}