解决 分页的 guid 枚举

Code/Be/Faster.Zheng.Winin/src/Faster.Zheng.Winin.Application.Contracts/AppBase/Filters/FilterExtensions.cs

@@ -71,10 +71,11 @@ public static class FilterExtensions
         {
             var parameter = Expression.Parameter(typeof(T), "p"); //创建参数p
             var member = Expression.PropertyOrField(parameter, filter.Column); //创建表达式中的属性或字段
-            // var propertyType = member.Type; //取属性类型,常量constant按此类型进行转换
-            //var constant = Expression.Constant(filterCondition.Value);//创建常数
 
             ConstantExpression constant = null;
+            //var propertyType = member.Type; //取属性类型,常量constant按此类型进行转换
+            //constant = Expression.Constant(filterCondition.Value);//创建常数
+
             if (filter.Action != "In" && filter.Action != "NotIn")
             {
                 constant = CreateConstantExpression(member.Type, filter.Value);
@@ -140,14 +141,17 @@ public static class FilterExtensions
     /// <returns></returns>
     private static ConstantExpression CreateConstantExpression(Type propertyType, string value)
     {
-        ConstantExpression constant;
+        ConstantExpression constant = null;
         try
         {
             if (propertyType.IsGenericType &&
                 propertyType.GetGenericTypeDefinition() == typeof(Nullable<>))
             {
-                var objValue = Convert.ChangeType(value, propertyType.GetGenericArguments()[0],
+
+                var objValue = Convert.ChangeType(ChangeTypeReturnValue(value, propertyType.GetGenericArguments()[0]),
+                    propertyType.GetGenericArguments()[0],
                     CultureInfo.InvariantCulture);
+
                 constant = Expression.Constant(objValue, propertyType);
             }
             else if (propertyType.IsEnum)
@@ -333,4 +337,34 @@ public static class FilterExtensions
         var inv = Expression.Invoke(condition, exp.Parameters);
         return Expression.Lambda<Func<T, bool>>(Expression.And(exp.Body, inv), exp.Parameters);
     }
+
+    /// <summary>
+    /// 转换传入的值，并将正确的值传出（解决 enum,guid）
+    /// </summary>
+    /// <param name="value"></param>
+    /// <param name="type"></param>
+    /// <returns></returns>
+    public static object ChangeTypeReturnValue(object value, Type type)
+    {
+        if (value == null && type.IsGenericType) return Activator.CreateInstance(type);
+        if (value == null) return null;
+        if (type == value.GetType()) return value;
+        if (type.IsEnum)
+        {
+            if (value is string)
+                return Enum.Parse(type, value as string);
+            else
+                return Enum.ToObject(type, value);
+        }
+        if (!type.IsInterface && type.IsGenericType)
+        {
+            Type innerType = type.GetGenericArguments()[0];
+            object innerValue = ChangeTypeReturnValue(value, innerType);
+            return Activator.CreateInstance(type, new object[] { innerValue });
+        }
+        if (value is string && type == typeof(Guid)) return new Guid(value as string);
+        if (value is string && type == typeof(Version)) return new Version(value as string);
+        if (!(value is IConvertible)) return value;
+        return Convert.ChangeType(value, type);
+    }
 }