Paging in ListView with Entity Framework - asp.net

Question

I am doing paging in a Listview with Entity Framework and I'm stuck when passing startindex and maxrows after clicking the next/prev button
This is my code
private List<WorkItem> Data(int startindex, int maxrows)
{
return (from x in ss.WorkItem
select x).OrderBy(p => p.WorkItemID).Skip(startindex).Take(maxrows).ToList();
}
protected void lvWorkItems_PagePropertiesChanging(object sender, PagePropertiesChangingEventArgs e)
{
this.DataPager1.SetPageProperties(e.StartRowIndex, e.MaximumRows, false);
lvWorkItems.DataSource = Data(e.StartRowIndex,e.MaximumRows);
lvWorkItems.DataBind();
}
My problem is how to pass startindex and maxrows when I click on next/Previous button.
Please help

Answer 1

Check it out please , it extension method :
public static IQueryable<T> MyPage<T, TResult>(this IQueryable<T> obj, int
page, int pageSize, System.Linq.Expressions.Expression<Func<T, TResult>>
keySelector, bool asc, out int rowsCount)
{
rowsCount = obj.Count();
if (asc)
{
return obj.OrderBy(keySelector).Skip(page * pageSize).Take(pageSize);
}
else
{
return obj.OrderByDescending(keySelector).Skip(page * pageSize).Take(pageSize);
}
}

Answer 2

This was exactly my problem too.
But my problem was solved by changing the structure of business output class method.
And of course, in this way you need to have the data output and number of rows.
And do not forget the issue relating to the same page layout data must be fetched from the database.
My class was designed to do the following.
using System.Collections.Generic;
using System.Linq;
using Andish.CSS.Common.Enum;
using AutoMapper;
using system.linq.dynamic;
namespace Andish.CSS.Common.Result.Implementation
{
public static class PagingResult
{
public static PageResult<K> ToPageResult<T, K>(this IQueryable<T> queryable, int rowCount,
int pageNumber, string sortField, DynamicLinqSortFieldKind
dynamicLinqSortFieldKind)
{
var allQueryRow = queryable.ToList<T>().Count();
var skipLen = (pageNumber - 1) * rowCount;
string orderKind = "";
orderKind = dynamicLinqSortFieldKind == DynamicLinqSortFieldKind.Ascending ? " Asc" : " Desc";
PageResult<K> pageResult = new PageResult<K>
{
PageNumber = pageNumber,
RowCount = rowCount,
Result = Mapper.Map<IList<K>>(queryable.OrderBy(sortField + orderKind)
.Skip(skipLen).Take(rowCount).ToList<T>()),
ResultRowCount = allQueryRow,
PageCount = allQueryRow % rowCount == 0 ? allQueryRow / rowCount : (allQueryRow / rowCount) + 1
};
return pageResult;
}
}
}
create this enum
public enum DynamicLinqSortFieldKind
{
Ascending = 0,
Descending = 1
}
And for use this extension Method do like this
and i have one result from class ExecutiveUnit and I want map this class to enother class
ExecutiveUnitModel .
i use automapper nuget.
var xresult = result.ToPageResult<ExecutiveUnit, ExecutiveUnitModel>(RowNumbers, pageNumber, "Code", DynamicLinqSortFieldKind.Ascending);