修改

IRaCIS.Core.Domain/Reading/ReadingQuestionSystem.cs

@@ -148,7 +148,7 @@ namespace IRaCIS.Core.Domain.Models
 		/// <summary>
 		/// 单位
 		/// </summary>
-		public string Unit { get; set; } = string.Empty;
+		public ValueUnit? Unit { get; set; }
 
 		[JsonIgnore]
 		[ForeignKey("ReadingQuestionCriterionSystemId")]

IRaCIS.Core.Domain/Reading/ReadingQuestionTrial.cs

@@ -181,7 +181,7 @@ namespace IRaCIS.Core.Domain.Models
 		/// <summary>
 		/// 单位
 		/// </summary>
-		public string Unit { get; set; } = string.Empty;
+		public ValueUnit? Unit { get; set; }
 
 		/// <summary>
 		/// 分页标准

IRaCIS.Core.Domain/Reading/ReadingTableQuestionSystem.cs

@@ -146,7 +146,7 @@ namespace IRaCIS.Core.Domain.Models
 		/// <summary>
 		/// 单位
 		/// </summary>
-		public string Unit { get; set; } = string.Empty;
+		public ValueUnit? Unit { get; set; }
 
 		[ForeignKey("DependParentId")]
 		public ReadingTableQuestionSystem DependParentQuestion { get; set; }

IRaCIS.Core.Domain/Reading/ReadingTableQuestionTrial.cs

@@ -150,7 +150,7 @@ namespace IRaCIS.Core.Domain.Models
 		/// <summary>
 		/// 单位
 		/// </summary>
-		public string Unit { get; set; } = string.Empty;
+		public ValueUnit? Unit { get; set; }
 
 		[JsonIgnore]
 		[ForeignKey("DependParentId")]