public void Navigate(PageChanges change)
{
uint totalRecords;
uint newPageSize;
if (this.MyQuery == null || this.cmbPageSizes.ItemsSource == null)
{
return;
}
totalRecords = (uint)MyQuery.Count();
newPageSize = (uint)cmbPageSizes.SelectedItem;
if (totalRecords == 0)
{
ItemsSource.Clear();
TotalPages = 1;
Page = 1;
StartRecord = 0;
EndRecord = 0;
}
else
{
TotalPages = (totalRecords / newPageSize) + (uint)((totalRecords % newPageSize == 0) ? 0 : 1);
}
uint newPage = 1;
switch (change)
{
case PageChanges.First:
if (Page == 1)
{
return;
}
break;
case PageChanges.Previous:
newPage = (Page - 1 > TotalPages) ? TotalPages : (Page - 1 < 1) ? 1 : Page - 1;
break;
case PageChanges.Current:
newPage = (Page > TotalPages) ? TotalPages : (Page < 1) ? 1 : Page;
break;
case PageChanges.Next:
newPage = (Page + 1 > TotalPages) ? TotalPages : Page + 1;
//(Page + 1) < 1 ? 1 :
break;
case PageChanges.Last:
if (Page == TotalPages)
{
return;
}
newPage = TotalPages;
break;
default:
break;
}
uint StartingIndex = (newPage - 1) * newPageSize;
StartRecord = StartingIndex + 1;
uint oldPage = Page;
RaisePreviewPageChange(Page, newPage);
Page = newPage;
TotalRecords = totalRecords;
ItemsSource.Clear();
IQueryable fetchData = MyQuery.Skip(Convert.ToInt32(StartingIndex)).Take(Convert.ToInt32(newPageSize));
var enumerator = fetchData.GetEnumerator();
while (enumerator.MoveNext())
{
ItemsSource.Add(enumerator.Current);
}
EndRecord = StartingIndex + Convert.ToUInt32(ItemsSource.Count);
RaisePageChanged(oldPage, Page);
}