Unity3D技术之资源数据库 (AssetDatabase)详解 - 纳金网

资源数据库 (AssetDatabase) 是允许您访问工程中的资源的 API。此外，其提供方法供您查找和加载资源，还可创建、删除和修改资源。Unity 编辑器 (Editor) 在内部使用资源数据库 (AssetDatabase) 追踪资源文件，并维护资源和引用资源的对象之间的关联。Unity 需要追踪工程文件夹发生的所有变化，如需访问或修改资源数据，您应始终使用资源数据库 (AssetDatabase) API，而非文件系统。资源数据库 (AssetDatabase) 接口仅适用于编辑器，不可用于内置播放器。和所有其他编辑器类一样，其只适用于置于编辑器 (Editor) 文件夹中的脚本（只在主要的资源 (Assets) 文件夹中创建名为“编辑器”的文件夹（不存在该文件夹的情况下））。

using UnityEngine;
using UnityEditor;
public class ImportAsset {
[MenuItem ("AssetDatabase/ImportExample")]
static void ImportExample ()
{
AssetDatabase.ImportAsset("Assets/Textures/texture.jpg", ImportAssetOptions.Default);
}
}

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如果将资源添加至场景或在检视 (Inspector) 面板中编辑这些资源，则编辑器仅在需要时加载资源。但是，您可以使用以下脚本加载和访问资源：AssetDatabase.LoadAssetAtPath、AssetDatabase.LoadMainAssetAtPath、AssetDatabase.LoadAllAssetRepresentationsAtPath 和 AssetDatabase.LoadAllAssetsAtPath。有关更多详细信息，请参阅脚本文档。

using UnityEngine;
using UnityEditor;
public class ImportAsset {
[MenuItem ("AssetDatabase/LoadAssetExample")]
static void ImportExample ()
{
Texture2D t = AssetDatabase.LoadAssetAtPath("Assets/Textures/texture.jpg", typeof(Texture2D)) as Texture2D;
}
}

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Unity 将保留资源文件的元数据，您决不可使用文件系统创建、移动或删除它们。相反，您应使用 AssetDatabase.Contains、AssetDatabase.CreateAsset、AssetDatabase.CreateFolder、AssetDatabase.RenameAsset、AssetDatabase.CopyAsset、AssetDatabase.MoveAsset、AssetDatabase.MoveAssetToTrash 和 AssetDatabase.DeleteAsset 进行上述操作。

public class AssetDatabaseIOExample {
[MenuItem ("AssetDatabase/FileOperationsExample")]
static void Example ()
{
string ret;
// Create
Material material = new Material (Shader.Find("Specular"));
AssetDatabase.CreateAsset(material, "Assets/MyMaterial.mat");
if(AssetDatabase.Contains(material))
Debug.Log("Material asset created");
// Rename
ret = AssetDatabase.RenameAsset("Assets/MyMaterial.mat", "MyMaterialNew");
if(ret == "")
Debug.Log("Material asset renamed to MyMaterialNew");
else
Debug.Log(ret);
// Create a Folder
ret = AssetDatabase.CreateFolder("Assets", "NewFolder");
if(AssetDatabase.GUIDToAssetPath(ret) != "")
Debug.Log("Folder asset created");
else
Debug.Log("Couldn't find the GUID for the path");
// Move
ret = AssetDatabase.MoveAsset(AssetDatabase.GetAssetPath(material), "Assets/NewFolder/MyMaterialNew.mat");
if(ret == "")
Debug.Log("Material asset moved to NewFolder/MyMaterialNew.mat");
else
Debug.Log(ret);
// Copy
if(AssetDatabase.CopyAsset(AssetDatabase.GetAssetPath(material), "Assets/MyMaterialNew.mat"))
Debug.Log("Material asset copied as Assets/MyMaterialNew.mat");
else
Debug.Log("Couldn't copy the material");
// Manually refresh the Database to inform of a change
AssetDatabase.Refresh();
Material MaterialCopy = AssetDatabase.LoadAssetAtPath("Assets/MyMaterialNew.mat", typeof(Material)) as Material;
// Move to Trash
if(AssetDatabase.MoveAssetToTrash(AssetDatabase.GetAssetPath(MaterialCopy)))
Debug.Log("MaterialCopy asset moved to trash");
// Delete
if(AssetDatabase.DeleteAsset(AssetDatabase.GetAssetPath(material)))
Debug.Log("Material asset deleted");
if(AssetDatabase.DeleteAsset("Assets/NewFolder"))
Debug.Log("NewFolder deleted");
// Refresh the AssetDatabase after all the changes
AssetDatabase.Refresh();
}
}

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