EntityFramework 动态构造排序 FuncIQueryableT, IOrderedQueryableT Dynamic

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
using System.Text;
/*** * jackchain * QQ:710782046* 2017-08-31* 动态构造OrderBy Linq序列* */namespace UFX.Tools
{public class ConvertExtOrderLinq{/// <summary>/// 动态转换为Linq排序/// </summary>/// <typeparam name="T"></typeparam>/// <param name="orderList">[aaa,bbb,ccc],[asc,asc,desc]</param>/// <returns></returns>public static Func<IQueryable<T>, IOrderedQueryable<T>> GetOrderBy<T>(List<string> orderColumn, List<string> orderDir){string ascKey = "OrderBy";string descKey = "OrderByDescending";Type typeQueryable = typeof(IQueryable<T>);ParameterExpression argQueryable = Expression.Parameter(typeQueryable, "jk");var outerExpression = Expression.Lambda(argQueryable, argQueryable);for (int i = 0; i < orderColumn.Count; i++){string columnName = orderColumn[i];string dirKey = orderDir[i].ToLower();IQueryable<T> query = new List<T>().AsQueryable<T>();Type type = typeof(T);ParameterExpression arg = Expression.Parameter(type, "uf");Expression expr = arg;if (columnName.Contains(".")){// support to be sorted on child fields. String[] childProperties = columnName.Split('.');System.Reflection.PropertyInfo property = typeof(T).GetProperty(childProperties[0]);MemberExpression propertyAccess = Expression.MakeMemberAccess(arg, property);for (int j = 1; j < childProperties.Length; j++){Type t = property.PropertyType;if (!t.IsGenericType){property = t.GetProperty(childProperties[j]);}else{property = t.GetGenericArguments().First().GetProperty(childProperties[i]);}type = property.PropertyType;expr = Expression.MakeMemberAccess(propertyAccess, property);//propertyAccess = Expression.MakeMemberAccess(propertyAccess, property);
                    }//property = type.GetProperty(propertyName);//propertyAccess = Expression.MakeMemberAccess(parameter, property);
                }else{PropertyInfo pi = type.GetProperty(columnName, BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance);expr = Expression.Property(expr, pi);type = pi.PropertyType;}LambdaExpression lambda = Expression.Lambda(expr, arg);string methodName = dirKey == "asc" ? ascKey : descKey;MethodCallExpression resultExp = Expression.Call(typeof(Queryable), methodName, new Type[] { typeof(T), type }, outerExpression.Body, Expression.Quote(lambda));outerExpression = Expression.Lambda(resultExp, argQueryable);ascKey = "ThenBy";descKey = "ThenByDescending";}return (Func<IQueryable<T>, IOrderedQueryable<T>>)outerExpression.Compile();}}
}

 如何使用？

[Action][Description("获取Grid数据")][HttpPost]public JsonResult Get(int start, int length, ExtGridSearch condition, ExtGridMutiSearch[] extCdns, ExtGridOrder[] order){int totalCount = 0;Func<IQueryable<DB_Color>, IOrderedQueryable<DB_Color>> dyncOrder = ConvertExtOrderLinq.GetOrderBy<DB_Color>(order.Select(s => s.column).ToList(), order.Select(s => s.dir).ToList());var list = WMFactory.DBColor.FindByPage(start, length, out totalCount,dyncOrder,null, condition, extCdns);return Json(new { data = list, recordsTotal = totalCount, recordsFiltered = totalCount }, JsonRequestBehavior.AllowGet);}

可结合Datatables 插件一起配合使用

 //主表格var DBRangeGrid = $('#DBRangeGrid').dataTable({scrollY: Global_MainTableHeight,scrollX: true,autoWidth: true,scrollCollapse: false,"processing": true,"serverSide": true,"ajax": {"url": "/Admin/Range/Get","type": "POST","data": function (d) {var dtCols = $('#DBRangeGrid').DataTable().settings().init().columns;var extOrder = [];var dtOrders = $('#DBRangeGrid').DataTable().order();$.each(dtOrders, function (i, item) {extOrder.push({ column: dtCols[item[0]].data, dir: item[1] });})d.order = extOrder;d.query = $("#txtSearchKey").val();d.fields = ['IsEnable', 'Year.YearName', 'Season.SeasonName', 'RangeName', 'Remark', 'CreateUser', ];}},"ordering": true,"order": [[8, "desc"]],"columns": [{"class": "cbcenter","orderable": false,"title": '<input type="checkbox" title="全选" class="selectAll" />',"data": "Id","width": "30px","render": function (data, type, row) {return '<input type="checkbox" class="ckbox" />';}},{"title": "启用", "data": "IsEnable", render: function (data, tp, row) {if (row.IsEnable == 1) {return "<span style='color:green'>启用</span>";} else {return "<span style='color:red'>禁用</span>";}}},{ "title": "年份", "data": "Year.YearName" },{ "title": "季节", "data": "Season.SeasonName" },{ "title": "月份", "data": "Month" },{ "title": "波段名称", "data": "RangeName" },{ "title": "备注", "data": "Remark" },{"data": "CreateUser", "title": "操作人", "width": "40px", "render": function (data, type, record) {if (record.ModifyUser != undefined && record.ModifyUser != "" && record.ModifyUser != null) return record.ModifyUser;else return data;}},{"data": "CreateTime", "title": "操作时间", "width": "120px", "render": function (data, type, record) {if (record.ModifyTime != undefined && record.ModifyTime != "" && record.ModifyTime != null) data = record.ModifyTime;var dt = eval("new " + data.substr(1, data.length - 2));return dt.Format("yyyy-MM-dd hh:mm:ss");}}]});