修改 可空类型传参处理，添加预处理模型绑定逻辑

IRaCIS.Core.API/Progranm.cs

@@ -96,6 +96,9 @@ builder.Services.AddJsonLocalization(options => options.ResourcesPath = "Resourc
 // 异常、参数统一验证过滤器、Json序列化配置、字符串参数绑型统一Trim()
 builder.Services.AddControllers(options =>
 {
+    // 插到最前，抢在默认绑定器之前
+    options.ModelBinderProviders.Insert(0, new NullableStructModelBinderProvider());
+
     options.Filters.Add<ModelActionFilter>();
     options.Filters.Add<ProjectExceptionFilter>();
     options.Filters.Add<UnitOfWorkFilter>();

IRaCIS.Core.API/_ServiceExtensions/NewtonsoftJson/NullToEmptyStringResolver.cs

@@ -3,8 +3,10 @@ using Newtonsoft.Json;
 using Newtonsoft.Json.Serialization;
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Reflection;
+using System.Reflection.Metadata;
 
 namespace IRaCIS.Core.API
 {
@@ -51,34 +53,69 @@ namespace IRaCIS.Core.API
     }
     public class NullToEmptyStringValueProvider : IValueProvider
     {
-        PropertyInfo _MemberInfo;
+        PropertyInfo _memberInfo;
+        private readonly bool _isNullable;
         public NullToEmptyStringValueProvider(PropertyInfo memberInfo)
         {
-            _MemberInfo = memberInfo;
+            _memberInfo = memberInfo;
+
         }
+
+
+
+        // DTO → JSON 返回前端的时候 处理null 变为"" 方便前端判断
         public object GetValue(object target)
         {
-            object result = _MemberInfo.GetValue(target);
-            if (_MemberInfo.PropertyType == typeof(string) && result == null) result = "";
-            else if (_MemberInfo.PropertyType == typeof(String[]) && result == null) result = new string[] { };
-            //else if (_MemberInfo.PropertyType == typeof(Nullable<Int32>) && result == null) result = 0;
-            //else if (_MemberInfo.PropertyType == typeof(Nullable<Decimal>) && result == null) result = 0.00M;
+            var result = _memberInfo.GetValue(target);
+            // 检查类型是否为string或string?
+            if (_memberInfo.PropertyType == typeof(string) && result == null)
+            {
 
+                #region 返回的时候处理 string string? null 为"" 不区分处理
+
+
+                //// 如果是string?类型，返回null  可以做到，但是得反射，因为 string string? 是编译层区分的
+
+                //var isNullable1 = _memberInfo.CustomAttributes
+                //   .Any(a => a.AttributeType.Name == "NullableAttribute");
+
+                ////var isNullable2 = _memberInfo.CustomAttributes
+                ////   .Any(a => a.AttributeType.FullName == "System.Runtime.CompilerServices.NullableAttribute");
+
+                //if (isNullable1)
+                //{
+                //    return result;
+                //}
+
+                #endregion
+
+
+                // 如果是string类型，返回空字符串
+                return string.Empty;
+            }
             return result;
         }
+
+
+        //影响 模型绑定时接收前端的值，同时影响 正常 JSON 序列化
         public void SetValue(object target, object value)
         {
 
-            if (_MemberInfo.PropertyType == typeof(string))
-            {
-                //去掉前后空格
-                _MemberInfo.SetValue(target, value == null ? string.Empty : value.ToString() == string.Empty ? value : value/*.ToString().Trim()*/);
+            _memberInfo.SetValue(target, value);
+
+
+            //// 会影响 string?  传递null 变为""
+
+            //if (_memberInfo.PropertyType == typeof(string))
+            //{
+            //    //去掉前后空格
+            //    _memberInfo.SetValue(target, value == null ? string.Empty : value.ToString() == string.Empty ? value : value/*.ToString().Trim()*/);
+            //}
+            //else
+            //{
+            //    _memberInfo.SetValue(target, value);
+            //}
 
-            }
-            else
-            {
-                _MemberInfo.SetValue(target, value);
-            }
 
         }
     }