Validate Input Attribute特性：用于任何屬性，并允自定義檢查器，靈活實現多種監測規則。使用此選項可強制執行正確的值（提供對應的返回值）。

常規寫法，實參輸入一個方法的名稱，一個對應的消息

    [ValidateInput("MustBeNull", "這個字段應該為空。")]
    public MyScripty DefaultMessage;
    private bool MustBeNull(MyScripty scripty)
    {
        return scripty == null;
    }

也可以使用$特殊標識符引用一個字段動態顯示提示信息，而且也可以明確指出需要提示信息的類型

    [ReadOnly]
    public string dynamicMessage = "這個物體不應該為空！";
    [ValidateInput("CheckGameObject", "$dynamicMessage", InfoMessageType.None)]
    public GameObject targetObj_None = null;
    [ValidateInput("CheckGameObject", "$dynamicMessage", InfoMessageType.Info)]
    public GameObject targetObj_Info = null;
    [ValidateInput("CheckGameObject", "$dynamicMessage", InfoMessageType.Warning)]
    public GameObject targetObj_Warning = null;
    [ValidateInput("CheckGameObject", "$dynamicMessage", InfoMessageType.Error)]
    public GameObject targetObj_Error = null;

    private bool CheckGameObject(GameObject tempObj)
    {
        return tempObj != null;
    }

當然也可以這么用

    [ValidateInput("IfNullIsFalse", "$Message", InfoMessageType.Warning)]
    public string Message = "Dynamic ValidateInput message";

    private bool IfNullIsFalse(string value)
    {
        return string.IsNullOrEmpty(value);
    }

也可以覆蓋默認的提示消息和消息類型

 [ValidateInput("HasMeshRendererDynamicMessage", "對應的函數中已經有消息，所以這個默認消息已經沒用")]
    public GameObject DynamicMessage;
    private bool HasMeshRendererDynamicMessage(GameObject gameObject, ref string errorMessage)
    {
        if (gameObject == null) return true;

        if (gameObject.GetComponentInChildren<MeshRenderer>() == null)
        {
            errorMessage = "\"" + gameObject.name + "\" 這玩應必須有一個 MeshRenderer 組件";//如果設置消息，則默認消息會被覆蓋
            return false;
        }
        return true;
    }

    [ValidateInput("HasMeshRendererDynamicMessageAndType", "對應的函數中已經有消息和類型，所以這個默認消息和類型已經沒用")]
    public GameObject DynamicMessageAndType;

    [InfoBox("Change GameObject value to update message type", InfoMessageType.Info)]
    public InfoMessageType MessageType;
    private bool HasMeshRendererDynamicMessageAndType(GameObject gameObject, ref string errorMessage, ref InfoMessageType? messageType)
    {
        if (gameObject == null) return true;

        if (gameObject.GetComponentInChildren<MeshRenderer>() == null)
        {
            errorMessage = "\"" + gameObject.name + "\" 要有一個 MeshRenderer 組件";//如果設置消息，則默認消息會被覆蓋
            messageType = this.MessageType;//如果設置消息類型，則默認消息類型會被覆蓋
            return false;
        }
        return true;
    }

完整示例代碼

using Sirenix.OdinInspector;
using UnityEngine;


public class ValidateInputAttributeExample : MonoBehaviour
{

    [ValidateInput("MustBeNull", "這個字段應該為空。")]
    public MyScripty DefaultMessage;
    private bool MustBeNull(MyScripty scripty)
    {
        return scripty == null;
    }

    [ReadOnly]
    public string dynamicMessage = "這個物體不應該為空！";
    [ValidateInput("CheckGameObject", "$dynamicMessage", InfoMessageType.None)]
    public GameObject targetObj_None = null;
    [ValidateInput("CheckGameObject", "$dynamicMessage", InfoMessageType.Info)]
    public GameObject targetObj_Info = null;
    [ValidateInput("CheckGameObject", "$dynamicMessage", InfoMessageType.Warning)]
    public GameObject targetObj_Warning = null;
    [ValidateInput("CheckGameObject", "$dynamicMessage", InfoMessageType.Error)]
    public GameObject targetObj_Error = null;

    private bool CheckGameObject(GameObject tempObj)
    {
        return tempObj != null;
    }

    [ValidateInput("IfNullIsFalse", "$Message", InfoMessageType.Warning)]
    public string Message = "Dynamic ValidateInput message";

    private bool IfNullIsFalse(string value)
    {
        return string.IsNullOrEmpty(value);
    }

    [ValidateInput("HasMeshRendererDynamicMessage", "對應的函數中已經有消息，所以這個默認消息已經沒用")]
    public GameObject DynamicMessage;
    private bool HasMeshRendererDynamicMessage(GameObject gameObject, ref string errorMessage)
    {
        if (gameObject == null) return true;

        if (gameObject.GetComponentInChildren<MeshRenderer>() == null)
        {
            errorMessage = "\"" + gameObject.name + "\" 這玩應必須有一個 MeshRenderer 組件";//如果設置消息，則默認消息會被覆蓋
            return false;
        }
        return true;
    }

    [ValidateInput("HasMeshRendererDynamicMessageAndType", "對應的函數中已經有消息和類型，所以這個默認消息和類型已經沒用")]
    public GameObject DynamicMessageAndType;

    [InfoBox("Change GameObject value to update message type", InfoMessageType.Info)]
    public InfoMessageType MessageType;
    private bool HasMeshRendererDynamicMessageAndType(GameObject gameObject, ref string errorMessage, ref InfoMessageType? messageType)
    {
        if (gameObject == null) return true;

        if (gameObject.GetComponentInChildren<MeshRenderer>() == null)
        {
            errorMessage = "\"" + gameObject.name + "\" 要有一個 MeshRenderer 組件";//如果設置消息，則默認消息會被覆蓋
            messageType = this.MessageType;//如果設置消息類型，則默認消息類型會被覆蓋
            return false;
        }
        return true;
    }


    private bool HasMeshRendererDefaultMessage(GameObject gameObject)
    {
        if (gameObject == null) return true;
        return gameObject.GetComponentInChildren<MeshRenderer>() != null;
    }
}

更多教程內容詳見：革命性Unity 編輯器擴展工具 --- Odin Inspector 系列教程