unity 下载好之后的图片视频，如何进行清理代码实现

在Unity中，可以使用以下代码来清理不再使用的资源：

using UnityEngine;
using UnityEditor;

public class ResourceCleaner : EditorWindow
{
    [MenuItem("Tools/Clean Unused Resources")]
    public static void ShowWindow()
    {
        var window = GetWindow<ResourceCleaner>();
        window.Show();
    }

    void OnGUI()
    {
        if (GUILayout.Button("Clean Unused Resources"))
        {
            CleanUnusedResources();
        }
    }

    private static void CleanUnusedResources()
    {
        string[] guids = AssetDatabase.FindAssets("t:Prefab t:Scene t:ScriptableObject t:Material t:Texture t:Sprite t:AnimationClip");
        int totalCount = guids.Length;
        int currentIndex = 0;

        foreach (string guid in guids)
        {
            currentIndex++;
            string assetPath = AssetDatabase.GUIDToAssetPath(guid);
            EditorUtility.DisplayProgressBar("Cleaning Unused Resources", $"Processing {currentIndex} of {totalCount}", (float)currentIndex / totalCount);
            Object asset = AssetDatabase.LoadAssetAtPath(assetPath, typeof(Object));
            if (asset != null)
            {
                var dependencies = AssetDatabase.GetDependencies(assetPath, false);
                var isUnused = true;
                foreach (var dependency in dependencies)
                {
                    if (!dependency.Contains(assetPath) && !AssetDatabase.GetAssetPath(dependency).StartsWith("Packages/"))
                    {
                        isUnused = false;
                        break;
                    }
                }
                if (isUnused)
                {
                    Debug.Log($"Cleaning Unused Resource - {assetPath}", asset);
                    AssetDatabase.DeleteAsset(assetPath);
                }
            }
        }
        EditorUtility.ClearProgressBar();
        AssetDatabase.Refresh();
    }
}

这个代码会在Unity的菜单栏中添加一个 `Tools/Clean Unused Resources` 的选项，点击后会删除所有未被使用的资源。请注意，在执行此操作之前，请确保您的项目没有依赖于这些资源，否则可能会导致项目中的错误。