AssetPreview.GetAssetPreview always return null

Unity Engine
1

Hi,

As the title says, AssetPreview.GetAssetPreview always return null. Why ?

			if (evt.type == EventType.DragPerform)
			{
				DragAndDrop.AcceptDrag ();
             
				foreach (UnityEngine.Object o in DragAndDrop.objectReferences)
				{
					GameObject go = o as GameObject;
					if (go)
					{
						Brick brick = go.GetComponent<Brick>();
						if (brick)
						{
							if (!Bricks.Contains(brick))
							{
								Texture2D tex = AssetPreview.GetAssetPreview(brick); //<------------------------------

//								while (tex == null) {}

//								tex.Resize(64, 64);
								AssetPreviews.Add(brick, tex);

								Debug.Log(brick.name + " dragged");
							} else Debug.LogError(o.name + " already added");
						} else Debug.LogError("Only Bricks can be added");
					} else Debug.LogError("Only GameObjects can be added");
				}
			}
2

I can’t see from your code anywhere in there that prove that this specific asset actually exist as a file inside the Assets folder.
Even worst, I doubt you could get the preview of a Component, as you cannot serialized a component individually.

3

The object exists as it’s dragged from the project view.
And it don’t even works with component’s gameobject, renderer, meshfilter, material, object or anything related and existing in this prefab I tried.

4

Now I do this in the OnInspectorGUI and it works fine :

GUIContent content = new GUIContent(AssetPreview.GetAssetPreview(brick.gameObject));