Duplicate resolution problem and Add a call function "Set default" on a settings scripts

Hi
I find a script on net for adding a settings résolution.
But the problem is :
-When i build for test, the resolution are duplicate by 3

-I want to add a call function like : public void SetDefault, so I could call it by a button and set the resolution that i would put in this function.

There is the script :

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.UI;
5. using UnityEditor;
6.  
7. public class ResolutionMenu : MonoBehaviour
8. {
9.     private const string resolutionWidthPlayerPrefKey = "ResolutionWidth";
10.     private const string resolutionHeightPlayerPrefKey = "ResolutionHeight";
11.     private const string resolutionRefreshRatePlayerPrefKey = "RefreshRate";
12.     private const string fullScreenPlayerPrefKey = "FullScreen";
13.     public Toggle fullScreenToggle;
14.     public Dropdown resolutionDropdown;
15.     Resolution[] resolutions;
16.     Resolution selectedResolution;
17.     void Start()
18.     {
19.         resolutions = Screen.resolutions;
20.         LoadSettings();
21.         CreateResolutionDropdown();
22.  
23.         fullScreenToggle.onValueChanged.AddListener(SetFullscreen);
24.         resolutionDropdown.onValueChanged.AddListener(SetResolution);
25.     }
26.  
27.     private void LoadSettings()
28.     {
29.         selectedResolution = new Resolution();
30.         selectedResolution.width = PlayerPrefs.GetInt(resolutionWidthPlayerPrefKey, Screen.currentResolution.width);
31.         selectedResolution.height = PlayerPrefs.GetInt(resolutionHeightPlayerPrefKey, Screen.currentResolution.height);
32.         selectedResolution.refreshRate = PlayerPrefs.GetInt(resolutionRefreshRatePlayerPrefKey, Screen.currentResolution.refreshRate);
33.  
34.         fullScreenToggle.isOn = PlayerPrefs.GetInt(fullScreenPlayerPrefKey, Screen.fullScreen ? 1 : 0) > 0;
35.  
36.         Screen.SetResolution(
37.             selectedResolution.width,
38.             selectedResolution.height,
39.             fullScreenToggle.isOn
40.         );
41.     }
42.  
43.     private void CreateResolutionDropdown()
44.     {
45.         resolutionDropdown.ClearOptions();
46.         List<string> options = new List<string>();
47.         int currentResolutionIndex = 0;
48.         for (int i = 0; i < resolutions.Length; i++)
49.         {
50.             string option = resolutions[i].width + " x " + resolutions[i].height;
51.             options.Add(option);
52.             if (Mathf.Approximately(resolutions[i].width, selectedResolution.width) && Mathf.Approximately(resolutions[i].height, selectedResolution.height))
53.             {
54.                 currentResolutionIndex = i;
55.             }
56.         }
57.         resolutionDropdown.AddOptions(options);
58.         resolutionDropdown.value = currentResolutionIndex;
59.         resolutionDropdown.RefreshShownValue();
60.     }
61.  
62.     public void SetFullscreen(bool isFullscreen)
63.     {
64.         Screen.fullScreen = isFullscreen;
65.         PlayerPrefs.SetInt(fullScreenPlayerPrefKey, isFullscreen ? 1 : 0);
66.     }
67.     public void SetResolution(int resolutionIndex)
68.     {
69.         selectedResolution = resolutions[resolutionIndex];
70.         Screen.SetResolution(selectedResolution.width, selectedResolution.height, Screen.fullScreen);
71.         PlayerPrefs.SetInt(resolutionWidthPlayerPrefKey, selectedResolution.width);
72.         PlayerPrefs.SetInt(resolutionHeightPlayerPrefKey, selectedResolution.height);
73.         PlayerPrefs.SetInt(resolutionRefreshRatePlayerPrefKey, selectedResolution.refreshRate);
74.     }
75. }
76.  

 

There are multiple resolution options with the same resolution because the Resolution struct also includes a refresh rate. For example you might have 3 resolution options like this:

Code (CSharp):

1. 1920x1080@60hz
2. 1920x1080@59.94hz
3. 1920x1080@144hz

 

I suspected it, how i can fix it ?