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
{ ///
/// 动态转换为Linq排序 ///
///
/// [aaa,bbb,ccc],[asc,asc,desc]
///
public static Func<IQueryable
{ 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”: ‘‘, “data”: “Id”, “width”: “30px”, “render”: function (data, type, row) { return ‘‘;
}
},
{ “title”: “启用”, “data”: “IsEnable”, render: function (data, tp, row) { if (row.IsEnable == 1) { return “启用“;
} else { return “禁用“;
}
}
},
{ “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”);
}
}
]
});
