Resolution Changer

using UnityEngine;
using TMPro;
using System.Collections.Generic;

public class ResolutionManager : MonoBehaviour
{
    public TMP_Dropdown resolutionDropdown;

    private bool resolutionsAdded = false;

    void Start()
    {
        resolutionDropdown.onValueChanged.AddListener(delegate
        {
            SetResolution(resolutionDropdown);
        });

        PopulateDropdown();
    }

    private void PopulateDropdown()
    {
        if (!resolutionsAdded)
        {
            resolutionDropdown.ClearOptions();

            List<string> uniqueResolutions = GetUniqueResolutions();

            foreach (string resolution in uniqueResolutions)
            {
                TMP_Dropdown.OptionData optionData = new TMP_Dropdown.OptionData(resolution);
                resolutionDropdown.options.Add(optionData);
            }

            resolutionDropdown.RefreshShownValue();

            resolutionsAdded = true;
        }
    }

    private List<string> GetUniqueResolutions()
    {
        HashSet<string> uniqueResolutionsSet = new HashSet<string>();

        foreach (Resolution resolution in Screen.resolutions)
        {
            string resolutionString = $"{resolution.width} x {resolution.height}";
            uniqueResolutionsSet.Add(resolutionString);
        }

        return new List<string>(uniqueResolutionsSet);
    }

    private void SetResolution(TMP_Dropdown dropdown)
    {
        string selectedResolutionString = dropdown.options[dropdown.value].text;
        string[] dimensions = selectedResolutionString.Split('x');

        if (dimensions.Length == 2 && int.TryParse(dimensions[0], out int width) && int.TryParse(dimensions[1], out int height))
        {
            Screen.SetResolution(width, height, Screen.fullScreen);
        }
    }
}