v0.9.13

- 增加 FreeSql.Extensions.JsonMap 扩展包，实现快速将对象映射为json字符串的方法；
- 优化 表达式解析未实现的错误提醒，如 $""；

Extensions/FreeSql.Extensions.JsonMap/JsonMapCore.cs

@@ -0,0 +1,58 @@
+using FreeSql.DataAnnotations;
+using Newtonsoft.Json;
+using System;
+using System.Collections.Concurrent;
+using System.Linq;
+using System.Linq.Expressions;
+using System.Reflection;
+using System.Text;
+
+namespace FreeSql.Extensions
+{
+    public static class JsonMapCore
+    {
+        static bool _isAoped = false;
+        static object _isAopedLock = new object();
+        static ConcurrentDictionary<Type, bool> _dicTypes = new ConcurrentDictionary<Type, bool>();
+        static MethodInfo MethodJsonConvertDeserializeObject = typeof(JsonConvert).GetMethod("DeserializeObject", new[] { typeof(string), typeof(Type) });
+        static MethodInfo MethodJsonConvertSerializeObject = typeof(JsonConvert).GetMethod("SerializeObject", new[] { typeof(object) });
+
+        /// <summary>
+        /// 当实体类属性为【对象】时，并且标记特性 [JsonMap] 时，该属性将以JSON形式映射存储
+        /// </summary>
+        /// <returns></returns>
+        public static void UseJsonMap(this IFreeSql that)
+        {
+            if (_isAoped == false)
+                lock(_isAopedLock)
+                    if (_isAoped == false)
+                    {
+                        _isAoped = true;
+
+                        FreeSql.Internal.Utils.GetDataReaderValueBlockExpressionSwitchTypeFullName.Add((LabelTarget returnTarget, Expression valueExp, Type type) =>
+                        {
+                            if (_dicTypes.ContainsKey(type)) return Expression.Return(returnTarget, Expression.TypeAs(Expression.Call(MethodJsonConvertDeserializeObject, Expression.Convert(valueExp, typeof(string)), Expression.Constant(type)), type));
+                            return null;
+                        });
+
+                        that.Aop.ConfigEntityProperty += new EventHandler<Aop.ConfigEntityPropertyEventArgs>((s, e) =>
+                        {
+                            if (e.Property.GetCustomAttribute<JsonMapAttribute>(false) != null)
+                            {
+                                e.ModifyResult.MapType = typeof(string);
+                                if (_dicTypes.TryAdd(e.Property.PropertyType, true))
+                                {
+                                    FreeSql.Internal.Utils.GetDataReaderValueBlockExpressionObjectToStringIfThenElse.Add((LabelTarget returnTarget, Expression valueExp, Expression elseExp, Type type) =>
+                                    {
+                                        return Expression.IfThenElse(
+                                            Expression.TypeEqual(valueExp, e.Property.PropertyType),
+                                            Expression.Return(returnTarget, Expression.Call(MethodJsonConvertSerializeObject, Expression.Convert(valueExp, typeof(object))), typeof(object)),
+                                            elseExp);
+                                    });
+                                }
+                            }
+                        });
+                    }
+        }
+    }
+}