GameWindow.IsMain

Returns

bool True if this window is the main application window.

Description

Returns true if this window is the main application window.

using UnityEngine;
using UnityEngine.Windowing;

public class IsMainWindowExample : MonoBehaviour
{
    void Start()
    {
        var window = GameWindow.Main;
        bool isMain = window.IsMain();
        Debug.Log($"Is main window: {isMain}");
    }
}