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CloudBuilder.Core/Extensions/SortCondition.cs

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+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Linq;
+using System.Linq.Expressions;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace CloudBuilder.Core.Extensions
+{
+    /// <summary>
+    /// 列表字段排序条件
+    /// </summary>
+    public class SortCondition
+    {
+        /// <summary>
+        /// 初始化一个<see cref="SortCondition"/>类型的新实例
+        /// </summary>
+        public SortCondition() : this(null)
+        { }
+
+        /// <summary>
+        /// 构造一个指定字段名称的升序排序的排序条件
+        /// </summary>
+        /// <param name="sortField">字段名称</param>
+        public SortCondition(string sortField)
+            : this(sortField, ListSortDirection.Ascending)
+        { }
+
+        /// <summary>
+        /// 构造一个排序字段名称和排序方式的排序条件
+        /// </summary>
+        /// <param name="sortField">字段名称</param>
+        /// <param name="listSortDirection">排序方式</param>
+        public SortCondition(string sortField, ListSortDirection listSortDirection)
+        {
+            SortField = sortField;
+            ListSortDirection = listSortDirection;
+        }
+
+        /// <summary>
+        /// 获取或设置 排序字段名称
+        /// </summary>
+        public string SortField { get; set; }
+
+        /// <summary>
+        /// 获取或设置 排序方向
+        /// </summary>
+        public ListSortDirection ListSortDirection { get; set; }
+    }
+
+
+    /// <summary>
+    /// 支持泛型的列表字段排序条件
+    /// </summary>
+    /// <typeparam name="T">列表元素类型</typeparam>
+    public class SortCondition<T> : SortCondition
+    {
+        /// <summary>
+        /// 使用排序字段 初始化一个<see cref="SortCondition"/>类型的新实例
+        /// </summary>
+        public SortCondition(Expression<Func<T, object>> keySelector)
+            : this(keySelector, ListSortDirection.Ascending)
+        { }
+
+        /// <summary>
+        /// 使用排序字段与排序方式 初始化一个<see cref="SortCondition"/>类型的新实例
+        /// </summary>
+        public SortCondition(Expression<Func<T, object>> keySelector, ListSortDirection listSortDirection)
+            : base(GetPropertyName(keySelector), listSortDirection)
+        { }
+
+        /// <summary>
+        /// 从泛型委托获取属性名
+        /// </summary>
+        private static string GetPropertyName(Expression<Func<T, object>> keySelector)
+        {
+            string param = keySelector.Parameters.First().Name;
+            string operand = ((dynamic)keySelector.Body).Operand.ToString();
+            operand = operand.Substring(param.Length + 1, operand.Length - param.Length - 1);
+            return operand;
+        }
+    }
+}