private static IPageable <T> AsPaging <T>(this ICollection <T> rows, Action <PagingDescriptor> computeAction)
where T : class
{
var descriptor = new PagingDescriptor((int)rows?.Count);
computeAction?.Invoke(descriptor);
return(new PagingCollection <T>(rows, descriptor));
}
public PagingCollection(ICollection <T> rows, PagingDescriptor descriptor)
{
rows.NotNull(nameof(rows));
descriptor.NotNull(nameof(descriptor));
// 如果未进行分页
if (rows.Count > descriptor.Size)
{
// 手动内存分页
_rows = rows
.Skip(descriptor.Skip)
.Take(descriptor.Size)
.ToList();
}
else
{
_rows = rows;
}
Descriptor = descriptor;
}
private static IPageable <TEntity> AsPagingCore <TEntity>(this IOrderedQueryable <TEntity> orderedQuery,
Action <PagingDescriptor> computeAction)
where TEntity : class
{
var descriptor = new PagingDescriptor(orderedQuery.Count());
computeAction.Invoke(descriptor);
IQueryable <TEntity> query = orderedQuery;
// 跳过条数
if (descriptor.Skip > 0)
{
query = query.Skip(descriptor.Skip);
}
// 获取条数
if (descriptor.Size > 0)
{
query = query.Take(descriptor.Size);
}
return(new PagingCollection <TEntity>(query.ToList(), descriptor));
}
private PagingCollection()
{
_rows = Array.Empty <T>();
Descriptor = new PagingDescriptor(0);
}
