asp.net 分页类

PaginatedList.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace VML.Web.Mvc {
public class PaginatedList<T> : List<T> {
public int Offset { get; private set; }
public int PageIndex { get; private set; }
public int PageSize { get; private set; }
public int TotalCount { get; private set; }
public int TotalPages { get; private set; }

/// <summary>
/// For manually paing.
/// </summary>
/// <param name="source">The result of current page</param>
/// <param name="totalCount"></param>
/// <param name="pageIndex"></param>
/// <param name="pageSize"></param>
public PaginatedList(IEnumerable<T> source, int totalCount, int pageIndex, int pageSize)
{
Offset = pageIndex * pageSize;
PageIndex = pageIndex;
PageSize = pageSize;
TotalCount = totalCount;
TotalPages = (int)Math.Ceiling(TotalCount / (double)PageSize);

this.AddRange(source);
}

public PaginatedList(IQueryable<T> source, int pageIndex, int pageSize) {
Offset = pageIndex * pageSize;
PageIndex = pageIndex;
PageSize = pageSize;
TotalCount = source.Count();
TotalPages = (int)Math.Ceiling(TotalCount / (double)PageSize);

this.AddRange(source.Skip(PageIndex * PageSize).Take(PageSize));
}

public PaginatedList(IQueryable<T> source, int pageSize, int? offset = null, int? pageIndex = null) {
if (offset != null) {
Offset = offset.Value;
PageIndex = (int)Math.Ceiling((decimal)Offset / pageSize);
} else if (pageIndex != null) {
Offset = pageIndex.Value * pageSize;
PageIndex = pageIndex.Value;
} else {
//offset = null and pageIndex = null
throw new ArgumentNullException("offset and pageIndex");
}
PageSize = pageSize;
TotalCount = source.Count();
TotalPages = (int)Math.Ceiling(TotalCount / (double)PageSize);

this.AddRange(source.Skip(Offset).Take(PageSize));
}

public bool HasPreviousPage {
get {
return (Offset > 0);
}
}

public bool HasNextPage {
get {
return (Offset + PageSize < TotalCount);
}
}

}
}