起動時に1度だけウィンドウを表示する

Hoge.cs

using UnityEngine;
using UnityEditor;

[UnityEditor.InitializeOnLoad]
public class Hoge : EditorWindow
{
	static readonly string tempFilePath = "Temp/unique File Name2";
	static Hoge()
	{
		if( System.IO.File.Exists(tempFilePath ) == false ){
			System.IO.File.Create(tempFilePath);

			EditorApplication.delayCall += Hoge.Init;
		}
	}

	static void Init()
	{
		Hoge.GetWindow<Hoge> ();
		EditorApplication.delayCall -= Hoge.Init;
	}
}