Description

Allow an editor class method to be initialized when Unity loads without action from the user.

For new code, use OnCodeInitializingAttribute instead for better resource pre-allocation timing. For more information, refer to Code reload and the code lifecycle in the manual.

using UnityEngine;
using UnityEditor;

class MyClass
{
    [InitializeOnLoadMethod]
    static void OnProjectLoadedInEditor()
    {
        Debug.Log("Project loaded in Unity Editor");
    }
}