Unity中无法从EditorWindow派生类创建ScriptableObject资产求助

问题描述 #

我正在开发一款Unity工具，功能是从Timeline提取数据，为DAW生成会话文件，并创建可作为游戏内音频事件的ScriptableObject。目前DAW会话文件生成正常，但创建ScriptableObject时遇到报错。

代码结构是用EditorWindow派生类调用一个MonoBehaviour类中的协程来创建ScriptableObject（协程用于下载静音音频文件并赋值给ScriptableObject字段，已排除协程本身的问题）。猜测可能是EditorWindow和MonoBehaviour的工作机制差异导致，但不确定。

相关代码 #

ReaperSessionTimeline（EditorWindow类） #

public class ReaperSessionTimeline:EditorWindow
{
    private void OnGUI()
    {
        timelineAsset = 
            EditorGUILayout.ObjectField("TimelineAsset", timelineAsset, typeof(TimelineAsset), false) as
                TimelineAsset;
        if(GUILayout.Button("Create"))
            this.StartCoroutine(audioEventCreator.CreateAudioEvent(timelineAsset);
    }
}

AudioEventCreator（MonoBehaviour类） #

namespace SettingsGenerator
{
    public class AudioEvent: ScriptableObject
    {
        public AudioClip clip;
    }

    public class AudioEventCreator: MonoBehaviour
    {
        AudioClip clip;
        public IEnumerator CreateAudioEvent(TimelineAsset tm)
        {
            string folderPath = $"{Application.dataPath}/Audio/sfx/cinematics/{tm.name}";
           
            if (!AssetDatabase.IsValidFolder(folderPath))
            {
                System.IO.Directory.CreateDirectory(folderPath);
            }
            // 为简洁起见移除了UnityWebRequest代码

            AudioEvent audioEvent = ScriptableObject.CreateInstance<SettingsGenerator.AudioEvent>();
            audioEvent.clip = clip;
            string name = AssetDatabase.GenerateUniqueAssetPath($"{folderPath}/{tm.name}.asset");
            AssetDatabase.CreateAsset(audioEvent, name);
            AssetDatabase.SaveAssets();
            AssetDatabase.Refresh();
            EditorUtility.FocusProjectWindow();
            Selection.activeObject = audioEvent;
        }
    } 
}

控制台报错信息 #

Couldn't create asset file!
UnityEngine.StackTraceUtility:ExtractStackTrace ()
SettingsGenerator.AudioEventCreator/<CreateAudioEvent>d__1:MoveNext () (at Assets/Editor/reaper_sessions_unity_timeline_tool/AudioEventCreator.cs:57)
Unity.EditorCoroutines.Editor.EditorCoroutine/YieldProcessor:MoveNext (System.Collections.IEnumerator) (at ./Library/PackageCache/com.unity.editorcoroutines@1.0.0/Editor/EditorCoroutine.cs:80)
Unity.EditorCoroutines.Editor.EditorCoroutine:ProcessIEnumeratorRecursive (System.Collections.IEnumerator) (at ./Library/PackageCache/com.unity.editorcoroutines@1.0.0/Editor/EditorCoroutine.cs:134)
Unity.EditorCoroutines.Editor.EditorCoroutine:MoveNext () (at ./Library/PackageCache/com.unity.editorcoroutines@1.0.0/Editor/EditorCoroutine.cs:115)
UnityEditor.EditorApplication:Internal_CallUpdateFunctions ()

另一条报错：

UnityException: Creating asset at path D:/Documents/unity_tools/Assets/Audio/sfx/cinematics/intro/intro.asset failed.
SettingsGenerator.AudioEventCreator+<CreateAudioEvent>d__1.MoveNext () (at Assets/Editor/reaper_sessions_unity_timeline_tool/AudioEventCreator.cs:57)
Unity.EditorCoroutines.Editor.EditorCoroutine+YieldProcessor.MoveNext (System.Collections.IEnumerator enumerator) (at ./Library/PackageCache/com.unity.editorcoroutines@1.0.0/Editor/EditorCoroutine.cs:80)
Unity.EditorCoroutines.Editor.EditorCoroutine.ProcessIEnumeratorRecursive (System.Collections.IEnumerator enumerator) (at ./Library/PackageCache/com.unity.editorcoroutines@1.0.0/Editor/EditorCoroutine.cs:134)
Unity.EditorCoroutines.Editor.EditorCoroutine:MoveNext () (at ./Library/PackageCache/com.unity.editorcoroutines@1.0.0/Editor/EditorCoroutine.cs:115)
UnityEditor.EditorApplication.Internal_CallUpdateFunctions () (at <fd823a7663ea4cdb840e6c898e2256ce>:0)

排查过非协程的常规方法，也尝试用Unity官方文档示例创建材质资产，均出现相同错误。不理解控制台中的MoveNext方法是什么，想知道问题根源是否和EditorWindow的特殊工作方式有关。

问题根源与解决方案 #

1. 路径格式错误（核心问题） #

AssetDatabase的API要求路径必须是相对于项目Assets文件夹的相对路径，而你用了Application.dataPath拼接出的绝对路径，这会直接导致AssetDatabase.CreateAsset失败。比如你现在的绝对路径D:/Documents/unity_tools/Assets/Audio/...，AssetDatabase需要的是Assets/Audio/sfx/cinematics/...这种格式。

2. AudioEventCreator继承MonoBehaviour的不合理性 #

在Editor工具中，无需继承MonoBehaviour——MonoBehaviour是用于运行时挂载在GameObject上的组件，Editor工具可以直接用普通静态类，避免不必要的生命周期问题。

3. 关于MoveNext的解释 #

MoveNext是C#迭代器（包括协程）的核心方法，协程本质是状态机，每次执行到yield语句时暂停，下次恢复时调用MoveNext继续执行。报错里的MoveNext只是说明错误发生在协程执行过程中，并非问题根源。

修正后的代码示例 #

修改AudioEventCreator为普通静态类

namespace SettingsGenerator
{
    public class AudioEvent : ScriptableObject
    {
        public AudioClip clip;
    }

    public static class AudioEventCreator
    {
        public static IEnumerator CreateAudioEvent(TimelineAsset tm)
        {
            // 拆分相对路径与绝对路径
            string relativeFolderPath = $"Audio/sfx/cinematics/{tm.name}";
            string absoluteFolderPath = $"{Application.dataPath}/{relativeFolderPath}";
           
            // 检查文件夹时使用Assets开头的相对路径
            if (!AssetDatabase.IsValidFolder($"Assets/{relativeFolderPath}"))
            {
                System.IO.Directory.CreateDirectory(absoluteFolderPath);
                // 创建目录后必须刷新AssetDatabase，让Unity识别新文件夹
                AssetDatabase.Refresh();
            }

            // 保留你的UnityWebRequest下载逻辑，下载完成后赋值clip变量

            AudioEvent audioEvent = ScriptableObject.CreateInstance<AudioEvent>();
            audioEvent.clip = clip;
            // 生成Assets开头的相对路径
            string assetPath = AssetDatabase.GenerateUniqueAssetPath($"Assets/{relativeFolderPath}/{tm.name}.asset");
            AssetDatabase.CreateAsset(audioEvent, assetPath);
            AssetDatabase.SaveAssets();
            AssetDatabase.Refresh();
            EditorUtility.FocusProjectWindow();
            Selection.activeObject = audioEvent;
            
            yield return null;
        }
    } 
}

修正ReaperSessionTimeline的协程调用（修复语法错误）

public class ReaperSessionTimeline : EditorWindow
{
    private TimelineAsset timelineAsset;

    private void OnGUI()
    {
        timelineAsset = 
            EditorGUILayout.ObjectField("TimelineAsset", timelineAsset, typeof(TimelineAsset), false) as
                TimelineAsset;
        // 增加空值判断，调用静态方法并修复括号语法错误
        if(GUILayout.Button("Create") && timelineAsset != null)
            this.StartCoroutine(AudioEventCreator.CreateAudioEvent(timelineAsset));
    }
}

额外注意事项 #

• 创建文件夹后必须调用AssetDatabase.Refresh()，否则Unity无法立即识别新文件夹，AssetDatabase.IsValidFolder会返回错误结果。
• 确保AudioEvent类不在Editor文件夹下（若AudioEventCreator在Editor目录，AudioEvent需放在普通Assets目录，否则打包时会丢失）。
• 协程在EditorWindow中使用this.StartCoroutine是完全可行的，之前的问题与协程本身无关。

内容的提问来源于stack exchange，提问作者wavesinaroom