Save Settings

Part of the Building Real Games section of Coddy's Unity journey. Lesson 25 of 60.

A setting is chosen once and expected back in every game after, so it belongs in PlayerPrefs. When the game starts, load the setting, put it on its control so the Settings screen shows it, and apply it to the game. When the player changes the control, apply the new value and save it. This toggle (using UnityEngine.UI;) shows or hides the on-screen timer, and since PlayerPrefs has no bool, it stores 1 for on and 0 for off:

public Toggle timerToggle;
public GameObject timerText;

void Start()
{
    bool show = PlayerPrefs.GetInt("ShowTimer", 1) == 1;
    timerToggle.isOn = show;
    timerText.SetActive(show);
    timerToggle.onValueChanged.AddListener(OnTimerToggled);
}

void OnTimerToggled(bool on)
{
    timerText.SetActive(on);
    PlayerPrefs.SetInt("ShowTimer", on ? 1 : 0);
    PlayerPrefs.Save();
}

onValueChanged passes the control's new value to the listener: a bool for a Toggle, a float for a Slider, whose position is slider.value. Setting isOn or value from code changes the control the way a player does, so when the value changes it calls the listeners too. That is why the listener is added after the load: added first, it would run on every start and save the loaded value straight back. SetIsOnWithoutNotify and SetValueWithoutNotify set a control without calling any listener.

The default decides what a new player gets. GetInt("ShowTimer", 1) shows the timer until the player turns it off; a default of 0 would hide it from everyone who never opened the settings. A float setting loads the same way with PlayerPrefs.GetFloat(key, defaultValue): GetFloat("MouseSensitivity", 1.5f) gives a new player 1.5. A volume setting goes on AudioListener.volume, Unity's master volume from 0 (silent) to 1 (full), which scales every sound in the game.

Challenge

Medium

Make the volume slider a saved setting under the key Volume.

In Start(), load PlayerPrefs.GetFloat("Volume", 0.8f), put it on slider.value and AudioListener.volume, and call ShowVolume.
Then add slider.onValueChanged.AddListener(OnVolumeChanged);.
In OnVolumeChanged, apply value to AudioListener.volume, show it, and save it with PlayerPrefs.SetFloat and PlayerPrefs.Save().

Press Play and move the slider, then Stop and Play: it stays where you left it. Then Check.

Try it yourself

using UnityEngine;
using UnityEngine.UI;
using TMPro;

public class VolumeSetting : MonoBehaviour
{
    public Slider slider;
    public TMP_Text volumeText;

    void Start()
    {
        // Load the saved volume, apply and show it, then listen to the slider
    }

    void OnVolumeChanged(float value)
    {
        // Apply, show and save the new volume
    }

    void ShowVolume(float volume)
    {
        volumeText.text = "Volume: " + Mathf.RoundToInt(volume * 100) + "%";
    }
}