Asset Selector Attribute 特性用于：在对象字段旁边添加一个小按钮，该按钮将向用户显示资产下拉列表，以便从属性中进行选择。

【AssetSelector】添加到对应的字段上即可

    [AssetSelector]
    public Material AnyAllMaterials;
    [AssetSelector]
    public Material[] ListOfAllMaterials;

【FlattenTreeView】是否开启树状图

    [PropertySpace(40)]
    [AssetSelector(FlattenTreeView = false)]//默认树状显示
    public PhysicMaterial TreeView;
    [AssetSelector(FlattenTreeView = true)]//非默认树状显示
    public PhysicMaterial NoTreeView;

【Paths】单路径或多路径查找

    [PropertySpace(40)]
    [AssetSelector(Paths = "Assets/TutorialAsset/ExampleScriptableObjects")]
    public ScriptableObject ScriptableObjectsFromFolder;
    [AssetSelector(Paths = "Assets/TutorialAsset/ExampleScriptableObjects|Assets/Plugins/Sirenix/Odin Inspector")]
    public ScriptableObject ScriptableObjectsFromMultipleFolders;

【Filter】自定义过滤条件

    [PropertySpace(40)]
    [AssetSelector(Filter = "New Animation t:AnimationClip l:自定义标签")]
    public UnityEngine.Object AssetDatabaseSearchFilters;

【DisableListAddButtonBehaviour】开启后加号不会出现树形下拉条以弹窗形式出现

    [Title("辅助性功能")]
    [AssetSelector(DisableListAddButtonBehaviour = true)] //开启后加号不会出现树形下拉条以弹窗形式出现
    public List<GameObject> DisableListAddButtonBehaviour;

【DrawDropdownForListElements】控制已经添加的Item是否含有下拉列表

    [PropertySpace(40)]
    [AssetSelector(DrawDropdownForListElements = false)]
    public List<GameObject> DisableListElementBehaviour_False;
    [AssetSelector(DrawDropdownForListElements = true)]
    public List<GameObject> DisableListElementBehaviour_True;

【ExcludeExistingValuesInList】去除已经含有的Item

    [PropertySpace(40)]
    [AssetSelector(ExcludeExistingValuesInList = true)]
    public List<GameObject> ExcludeExistingValuesInList_True;
    [AssetSelector(ExcludeExistingValuesInList = false)]
    public List<GameObject> ExcludeExistingValuesInList_False;

【IsUniqueList】开启列表勾选模式（这个关键字在Odin的很多特性中都有）

    [PropertySpace(40)]
    [AssetSelector(IsUniqueList = true)]
    public List<GameObject> DisableUniqueListBehaviour_True;
    [AssetSelector(IsUniqueList = false)]
    public List<GameObject> DisableUniqueListBehaviour_False;

【ExpandAllMenuItems】下拉列表是否强制展开

    [PropertySpace(40)]
    [AssetSelector(ExpandAllMenuItems = true)]//下拉条是否展开
    public List<GameObject> ExpandAllMenuItems_True;
    [AssetSelector(ExpandAllMenuItems = false)]
    public List<GameObject> ExpandAllMenuItems_False;

【DropdownTitle】下拉列表标题

    [PropertySpace(40)]
    [AssetSelector(DropdownTitle = "最定义下拉列表标题")]
    public List<GameObject> CustomDropdownTitle;

完整示例代码

using UnityEngine;

using Sirenix.OdinInspector;
using System;
using System.Collections.Generic;
public class AssetSelectorAttributeExample : MonoBehaviour
{
    [AssetSelector]
    public Material AnyAllMaterials;
    [AssetSelector]
    public Material[] ListOfAllMaterials;

    [PropertySpace(40)]
    [AssetSelector(FlattenTreeView = false)]//默认树状显示
    public PhysicMaterial TreeView;
    [AssetSelector(FlattenTreeView = true)]//非默认树状显示
    public PhysicMaterial NoTreeView;


    [PropertySpace(40)]
    [AssetSelector(Paths = "Assets/TutorialAsset/ExampleScriptableObjects")]
    public ScriptableObject ScriptableObjectsFromFolder;
    [AssetSelector(Paths = "Assets/TutorialAsset/ExampleScriptableObjects|Assets/Plugins/Sirenix/Odin Inspector")]
    public ScriptableObject ScriptableObjectsFromMultipleFolders;

    [PropertySpace(40)]
    [AssetSelector(Filter = "New Animation t:AnimationClip l:自定义标签")]
    public UnityEngine.Object AssetDatabaseSearchFilters;

    [Title("辅助性功能")]
    [AssetSelector(DisableListAddButtonBehaviour = true)] //开启后加号不会出现树形下拉条以弹窗形式出现
    public List<GameObject> DisableListAddButtonBehaviour;

    [PropertySpace(40)]
    [AssetSelector(DrawDropdownForListElements = false)]
    public List<GameObject> DisableListElementBehaviour_False;
    [AssetSelector(DrawDropdownForListElements = true)]
    public List<GameObject> DisableListElementBehaviour_True;

    [PropertySpace(40)]
    [AssetSelector(ExcludeExistingValuesInList = true)]
    public List<GameObject> ExcludeExistingValuesInList_True;
    [AssetSelector(ExcludeExistingValuesInList = false)]
    public List<GameObject> ExcludeExistingValuesInList_False;

    [PropertySpace(40)]
    [AssetSelector(IsUniqueList = true)]
    public List<GameObject> DisableUniqueListBehaviour_True;
    [AssetSelector(IsUniqueList = false)]
    public List<GameObject> DisableUniqueListBehaviour_False;

    [PropertySpace(40)]
    [AssetSelector(ExpandAllMenuItems = true)]//下拉条是否展开
    public List<GameObject> ExpandAllMenuItems_True;
    [AssetSelector(ExpandAllMenuItems = false)]
    public List<GameObject> ExpandAllMenuItems_False;

    [PropertySpace(40)]
    [AssetSelector(DropdownTitle = "最定义下拉列表标题")]
    public List<GameObject> CustomDropdownTitle;
}

更多教程内容详见：革命性Unity 编辑器扩展工具 --- Odin Inspector 系列教程