Required Attribute特性：用于任何對象屬性，如果對應屬性沒有賦值，則在檢查器中出現對應的提示消息。

直接添加特性

    [Required]
    public GameObject MyGameObject;

也可以自定義消息

    [Required("自定義錯誤消息.")]
    public Rigidbody MyRigidbody;

當然可以使用$關鍵字使用動態消息

    public string DynamicMessage = "Dynamic Message";
    [Required("$DynamicMessage")]
    public GameObject GameObject_DynamicMessage;

    [Required("$ReturnStringFunction")]
    public GameObject GameObject_DynamicMessage1;
    public string ReturnStringFunction()
    {
        return "菜鳥海瀾";
    }

也可以顯示不同的消息類型，但是None和Info不顯示，目前不知道就是這么設定的還是BUG？、

    [Required("$DynamicMessage", InfoMessageType.None)]
    public GameObject GameObject_None;
    [Required("$DynamicMessage", InfoMessageType.Info)]
    public GameObject GameObject_Info;
    [Required("$DynamicMessage", InfoMessageType.Warning)]
    public GameObject GameObject_Warning;
    [Required("$DynamicMessage",InfoMessageType.Error)]
    public GameObject GameObject_Error;

完整示例代碼

using Sirenix.OdinInspector;
using UnityEngine;

public class RequiredExample : MonoBehaviour
{

    [Required]
    public GameObject MyGameObject;

    [Required("自定義錯誤消息.")]
    public Rigidbody MyRigidbody;


    public string DynamicMessage = "Dynamic Message";
    [Required("$DynamicMessage")]
    public GameObject GameObject_DynamicMessage;

    [Required("$ReturnStringFunction")]
    public GameObject GameObject_DynamicMessage1;
    public string ReturnStringFunction()
    {
        return "菜鳥海瀾";
    }

    [Required("$DynamicMessage", InfoMessageType.None)]
    public GameObject GameObject_None;
    [Required("$DynamicMessage", InfoMessageType.Info)]
    public GameObject GameObject_Info;
    [Required("$DynamicMessage", InfoMessageType.Warning)]
    public GameObject GameObject_Warning;
    [Required("$DynamicMessage",InfoMessageType.Error)]
    public GameObject GameObject_Error;
}

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