C＃通过expando对象的动态LINQ顺序 [英] C# Dynamic linq order by expando object
问题描述
我有一个情况，我需要根据数据库表升序或降序的配置动态排序
我的数据库表有列名我需要排序和排序顺序。
我有一个对象列表，其中每个对象都有一个ExpandoObject。
我的类看起来像这样
public class Customer：Base {
public string Name {get; set;}
public string City {get; set;}
public string Address {get; set;}
public string State {get; set;}
public int Id {get; set;}
public DateTime Dob {get; set;}
public int Age {get; set;}
public dynamic custom = new ExpandoObject（）;
}
Customer类有一个ExpandoObject，以便存储额外的属性
我有一个具有排序配置的表，它有列名和排序顺序
，例如
ColName SortOrder
City Asc
名称Desc
custom_XYZ Asc //这意味着这是一个自定义列
以custom_（属性名称）开头的所有列名称都存储在expando对象中是一个字典。
现在我使用下面的代码来做动态的linq orderBy
var sortList; //此列表具有类型为{string：ColName：bool：Asc}的排序列表
var customers; //保存expando中带有自定义字段的客户对象列表
var col = sortList [0];
var propertyInfo = typeof（Student）.GetProperty（col.ColName）;
var sortedData = customers.OrderBy（x => propertyInfo.GetValue（x，null））;
for（int i = 1; i< sortList.Count（） - 1; i ++）{
var col1 = sortList [i];
var prop = typeof（Student）.GetProperty（col1.ColName）;
if（col1.asc）
sortedData = sortedData.ThenBy（n => param2.GetValue（n，null））;
else
sortedData = sortedData.ThenByDescending（n => param2.GetValue（n，null））;
}
有人可以帮助我如何在自定义对象类型ExpandoObject。
ExpandoObject实际上将属性作为一个字典内部包装，所以有人可以帮助我如何基于对应于一个字典的值排序整个对象
$ p public static IOrderedEnumerable< Customer> OrderByCustomer（IEnumerable< Customer> enu，Column column）
{
Func< Customer，object>选择器
if（！column.ColName.StartsWith（custom_））
{
var propertyInfo = typeof（Customer）.GetProperty（column.ColName）;
selector = x => propertyInfo.GetValue（x，null）;
}
else
{
selector = x =>
{
object obj;
（（IDictionary< string，object>）x.custom）.TryGetValue（column.ColName.Substring（custom _Length），out obj）;
return obj;
};
}
IOrderedEnumerable< Customer> ordered = enu as IOrderedEnumerable< Customer> ;;
if（ordered == null）
{
if（column.SortOrder == SortOrder.Asc）
{
return enu.OrderBy（selector ）;
}
else
{
return enu.OrderByDescending（selector）;
}
}
if（column.SortOrder == SortOrder.Asc）
{
return ordered.ThenBy（selector）;
}
else
{
return ordered.ThenByDescending（selector）;
}
}
使用它像：
var sortedList = new [] {
new Column {ColName =Name，SortOrder = SortOrder.Asc}，
new Column {ColName =custom_Secret，SortOrder = SortOrder.Asc}，
};
var col = sortedList [0];
var sortedData = OrderByCustomer（customers，sortedList [0]）;
for（int i = 1; i< sortedList.Length; i ++）
{
sortedData = OrderByCustomer（sortedData，sortedList [i]）;
}
var result = sortedData.ToArray（）;
请注意，您使用 OrderByCustomer 第一个排序（它使用 OrderBy / OrderByDescending ）和其他子排序 ThenBy / ThenByDescending ）
I have a situation where I will need to sort dynamically based on a configuration from database table ascending or descending
My Database table has column name That I will need to sort and sort order.
I have a list of objects, in which each object has an ExpandoObject.
My Class looks like this
public class Customer: Base {
public string Name { get; set;}
public string City { get; set;}
public string Address { get; set;}
public string State { get; set;}
public int Id { get; set;}
public DateTime Dob { get; set;}
public int Age{ get; set;}
public dynamic custom = new ExpandoObject();
}
Customer class has an ExpandoObject in order to store additional properties also called as custom properties which are configurable per Customer.
I have a table which has configurations for sorting, it has the Column names and sort order such as
ColName SortOrder
City Asc
Name Desc
custom_XYZ Asc //this means this is a custom column
All the column names starting with custom_(Property Name) are stored in expando object which in turn is a dictionary.
Right now I am using the below code to do dynamic linq orderBy
var sortList; // this list has the sorting list with type {string:ColName: bool:Asc}
var customers; //holds the list of customer objects with custom fields in expando
var col = sortList[0];
var propertyInfo = typeof(Student).GetProperty(col.ColName);
var sortedData= customers.OrderBy(x => propertyInfo.GetValue(x, null));
for(int i = 1; i<sortList.Count()-1;i++){
var col1 = sortList[i];
var prop = typeof(Student).GetProperty(col1.ColName);
if(col1.asc)
sortedData = sortedData.ThenBy(n => param2.GetValue(n, null));
else
sortedData = sortedData.ThenByDescending(n => param2.GetValue(n, null));
}
could someone help me on how could I sort data in custom object which is of type ExpandoObject.
ExpandoObject actually wraps the properties as a Dictionary internally so could someone help me on how could I sort the whole object based on the value of a Dictionary corresponding to a Key (which is columnName)
You could try with something like:
public static IOrderedEnumerable<Customer> OrderByCustomer(IEnumerable<Customer> enu, Column column)
{
Func<Customer, object> selector;
if (!column.ColName.StartsWith("custom_"))
{
var propertyInfo = typeof(Customer).GetProperty(column.ColName);
selector = x => propertyInfo.GetValue(x, null);
}
else
{
selector = x =>
{
object obj;
((IDictionary<string, object>)x.custom).TryGetValue(column.ColName.Substring("custom_".Length), out obj);
return obj;
};
}
IOrderedEnumerable<Customer> ordered = enu as IOrderedEnumerable<Customer>;
if (ordered == null)
{
if (column.SortOrder == SortOrder.Asc)
{
return enu.OrderBy(selector);
}
else
{
return enu.OrderByDescending(selector);
}
}
if (column.SortOrder == SortOrder.Asc)
{
return ordered.ThenBy(selector);
}
else
{
return ordered.ThenByDescending(selector);
}
}
use it like:
var sortedList = new[] {
new Column { ColName = "Name", SortOrder = SortOrder.Asc },
new Column { ColName = "custom_Secret", SortOrder = SortOrder.Asc },
};
var col = sortedList[0];
var sortedData = OrderByCustomer(customers, sortedList[0]);
for (int i = 1; i < sortedList.Length; i++)
{
sortedData = OrderByCustomer(sortedData, sortedList[i]);
}
var result = sortedData.ToArray();
Note that you use my OrderByCustomer both for the first ordering (where it uses the OrderBy/OrderByDescending) and for the other sub-ordering (where it uses the ThenBy/ThenByDescending)
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