Unity implements scene loading progress bar

1. Effect display

2. Scene construction

3. Code

1. SceneNameDrawer.cs: You can choose the scene you want to switch to avoid manual input errors

using UnityEngine; // 引入Unity引擎命名空间
using UnityEditor; // 引入Unity编辑器命名空间
using System.Linq; // 引入LINQ命名空间，用于处理集合

public class SceneNameAttribute : PropertyAttribute {
    
     } // 场景名称属性，继承自PropertyAttribute

#if UNITY_EDITOR // 编译指令，如果是在Unity编辑器中编译则进入下面的代码块
[CustomPropertyDrawer(typeof(SceneNameAttribute))] // 自定义属性绘制器，指定处理SceneNameAttribute属性
public class SceneNameDrawer : PropertyDrawer // 场景名称绘制器，继承自PropertyDrawer
{
    
    
    public override void OnGUI(Rect position, SerializedProperty property, GUIContent label) // 重写PropertyDrawer类的OnGUI方法
    {
    
    
        // 获取Build Settings中的所有场景，过滤掉路径为空的场景并提取场景名称，生成场景名称数组
        var scenes = EditorBuildSettings.scenes
            .Where(s => !string.IsNullOrEmpty(s.path))
            .Select(s => System.IO.Path.GetFileNameWithoutExtension(s.path))
            .ToArray();

        // 获取当前序列化属性的值，查找其在场景名称数组中的索引
        var index = Mathf.Max(0, System.Array.IndexOf(scenes, property.stringValue));

        // 在编辑器中绘制一个弹出式下拉菜单，用于选择场景
        EditorGUI.BeginChangeCheck(); // 开始检查编辑器UI是否发生了变化
        index = EditorGUI.Popup(position, label.text, index, scenes); // 绘制弹出式下拉菜单
        if (EditorGUI.EndChangeCheck()) // 如果编辑器UI发生了变化
        {
    
    
            property.stringValue = scenes[index]; // 更新序列化属性的值
        }
    }
}
#endif // 结束编译指令

2. Progress bar.cs: Realize the progress bar scrolling

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.SceneManagement;

public class 进度条 : MonoBehaviour
{
    
    
    public Slider slider;

    public GameObject startButton;

    public bool really = true;//是否是真实的加载

    [SceneName]
    public string sceneName; //你想要切换的场景

    private float currentProgress;//当前进度

    private float loadingTime = 2;//虚假的加载时间

    private AsyncOperation operation;

    // Start is called before the first frame update
    void Start()
    {
    
    
        startButton.SetActive(false);

        startButton.GetComponent<Button>().onClick.AddListener(OnStartButtonClick);

        currentProgress = 0;

        slider.value = currentProgress;

        if (really)
        {
    
    
            operation = SceneManager.LoadSceneAsync(sceneName);
            operation.allowSceneActivation = false;
        }
    }

    // Update is called once per frame
    void Update()
    {
    
    
        if (!really)
        {
    
    
            currentProgress += Time.deltaTime / loadingTime;
            if (currentProgress > 1)
            {
    
    
                currentProgress = 1;
            }
        }
        else
        {
    
    
            currentProgress = Mathf.Clamp01(operation.progress / 0.9f);
        }
        OnSliderValueChange(currentProgress);
    }

    private void OnStartButtonClick()
    {
    
    
        if (!really)
        {
    
    
            SceneManager.LoadScene(sceneName);
        }
        else
        {
    
    
            operation.allowSceneActivation = true;
        }
    }

    private void OnSliderValueChange(float value)//改变滑动条的值
    {
    
    
        slider.value = value;
        if (value >= 1)
        {
    
    
            startButton.SetActive(true);
        }
    }
}