Unity場景加載進度條

實現思路：
加載器加載場景 -> 加載進度通知UI -> 更新UI進度

1.場景加載器:
SceneLoader.cs

using UnityEngine;
using System.Collections;
using UnityEngine.SceneManagement;

/// <summary>
/// 場景加載器
/// <param>ZhangYu 2017-06-15</param>
/// </summary>
public class SceneLoader : MonoBehaviour {

    // 場景名稱
    public string sceneName;
    // 進度事件接收者
    public Transform progressReceiver;
    // 加載進度
    private float _progress = 0;
    // 異步加載信息
    private AsyncOperation async;

    /// <summary> 加載當前配置的場景 </summary>
    public void load(){
        loadScene(sceneName);
    }

    /// <summary> 加載場景 </summary>
    /// <param name="sceneName">場景名稱</param>
    public void loadScene(string sceneName) {
        if (isLoading) return;
        this.sceneName = sceneName;
        _progress = 0;
        enabled = true;
        StartCoroutine(loading());
        if (progressReceiver != null) {
            progressReceiver.gameObject.SetActive(true);
            progressReceiver.SendMessage("onProgress", progress, SendMessageOptions.DontRequireReceiver);
        }
    }

    /// <summary> 開啓協程加載場景 </summary>
    private IEnumerator loading() {
        async = SceneManager.LoadSceneAsync(sceneName);
        yield return async;
        if (progressReceiver != null) progressReceiver.gameObject.SetActive(false);
        async = null;
    }

    #if UNITY_EDITOR
    // 屏蔽Animation關鍵幀事件中的loading()可選項
    private IEnumerator loading(string sceneName) {
        yield return null;
    }
    #endif

    /// <summary> 正在加載 </summary>
    public bool isLoading {
        get { return async != null; }
    }

    /// <summary> 加載進度 </summary>
    public float progress {
        get { return _progress; }
    }

    /// <summary> 更新加載進度 </summary>
    private void Update() {
        if (async == null) {
            enabled = false;
        } else {
            // 加載進度值範圍是0~0.9 這裏作下處理
            float progress = async.progress;
            progress = progress < 0.9f ? progress * (10 / 9f) : 1;
            _progress = progress;
            if (progressReceiver != null) {
                progressReceiver.SendMessage("onProgress", progress, SendMessageOptions.DontRequireReceiver);
            }
        }
    }

}

2.進度條:
ProgressBar.cs

using System;
using UnityEngine;
using UnityEngine.UI;

/// <summary>
/// 進度條
/// <param>ZhangYu 2017-06-15</param>
/// </summary>
public class ProgressBar : MonoBehaviour, IOnProgress {

    // 進度條
    public Slider slider;
    // 進度文本
    public Text text;

    #if UNITY_EDITOR
    private void Reset() {
        slider = GetComponentInChildren<Slider>();
        text = GetComponentInChildren<Text>();
    }
    #endif

    /// <summary> 進度變動事件 </summary>
    public void onProgress(float progress) {
        if (slider != null) slider.value = progress;
        if (text != null) text.text = (int)(progress * 100) + "%";
    }

}

3.進度更新接口:
IOnProgress.cs

/// <summary>
/// 進度更新接口
/// <param>ZhangYu 2017-06-15</param>
/// </summary>
public interface IOnProgress {

    /// <summary> 進度更新事件 </summary>
    /// <param name="progress">進度百分比</param>
    void onProgress(float progress);

}

附送場景加載器 編輯器：
SceneLoaderEditor.cs

using UnityEditor;
using UnityEngine;

/// <summary>
/// 場景加載器 編輯器
/// <para>ZhangYu 2018-06-15</para>
/// </summary>
[CanEditMultipleObjects]
[CustomEditor(typeof(SceneLoader))]
public class SceneLoaderEditor : Editor {

    public override void OnInspectorGUI() {
        // 重繪GUI
        SceneLoader loader = (SceneLoader)target;
        EditorGUI.BeginChangeCheck();
        drawProperty("sceneName", "場景名稱");
        drawProperty("progressReceiver", "進度事件接收者");
        if (loader.isLoading) EditorGUILayout.FloatField("加載進度", loader.progress);
        if (EditorGUI.EndChangeCheck()) serializedObject.ApplyModifiedProperties();
    }

    private void drawProperty(string property, string label) {
        EditorGUILayout.PropertyField(serializedObject.FindProperty(property), new GUIContent(label), true);
    }

}

附送進度條 編輯器：
ProgressBarEditor.cs

using UnityEditor;
using UnityEngine;

/// <summary>
/// 進度條 編輯器
/// <para>ZhangYu 2018-06-15</para>
/// </summary>
[CanEditMultipleObjects]
[CustomEditor(typeof(ProgressBar))]
public class ProgressBarEditor : Editor {

    public override void OnInspectorGUI() {
        // 重繪GUI
        EditorGUI.BeginChangeCheck();
        drawProperty("slider", "進度條");
        drawProperty("text", "進度文本");
        if (EditorGUI.EndChangeCheck()) serializedObject.ApplyModifiedProperties();
    }

    private void drawProperty(string property, string label) {
        EditorGUILayout.PropertyField(serializedObject.FindProperty(property), new GUIContent(label), true);
    }

}