IDataStore.SortByDescending<TModel>(Func<TModel, object> keySelector) Method

.NET Standard 2.x

Sorts the rows of the primary buffer in the DataStore by a key in the descending order.

Namespace: DWNet.Data

Assembly: DWNet.Data.dll

Syntax

IOrderable<TModel> SortByDescending<TModel>(Func<TModel, object> keySelector);

Type Parameters

TModel

The type of a model class that matches with the current DataObject.

Parameters

keySelector Func<TModel, long>

A function to extract the key from a row.

Returns

DWNet.Data.IOrderable<TModel>

Returns an IOrderable<TModel> object which provides methods to add other sorting conditions or execute sort.

Examples

The following code example sorts data records by budget in the descending order.

using Appeon.ApiDoc.Models;
using DWNet.Data;
using System;

namespace Appeon.ApiDoc.IDataStoreExamples
{
    public class SortByDescendingExample
    {
        private readonly SchoolContext _context;

        public SortByDescendingExample(SchoolContext dataContext)
        {
            // Sets the data context
            _context = dataContext;
        }

        public void Example()
        {
            // Instantiates a DataStore object with datawindow: d_department.
            var datastore = new DataStore("d_department", _context);

            datastore.Retrieve();

            foreach (var item in datastore)
            {
                Console.WriteLine("Before Sort, Budget:{0}", ((D_Department)item).Budget);
            }

            // Specifies key in descending order.
            datastore.SortByDescending<D_Department>(a => a.Budget);
            // Sorts DataStore in descending order.
            datastore.Sort();

            foreach (var item in datastore)
            {
                Console.WriteLine("After Sort, Budget:{0}", ((D_Department)item).Budget);
            }

            /*This code produces the following output:
            
            Before Sort, Budget: 350000.00
            Before Sort, Budget: 120000.00
            Before Sort, Budget: 200000.00
            Before Sort, Budget: 250000.00
            After Sort, Budget: 350000.00
            After Sort, Budget: 250000.00
            After Sort, Budget: 200000.00
            After Sort, Budget: 120000.00
            */
        }
    }
}

Example Refer To

Model Class: D_Department
DataWindow File: d_department