Paging of data

The Qlik Sense .NET SDK provides classes for performing paging on hypercubes and list objects. The classes extending the DataPager class provide interfaces for traversing data from pageable objects (hypercubes and list objects).

            var myListboxPager = myListbox.ListObjectPager;

You can either get the data for specific pages, move the page manually by calling the MoveCurrentPages method and then getting the data, or use the predefined convenience functions for moving across the data and retrieving the data.

Example: Get data at a specific page (the 20 top rows of column 1)

            myListboxPager.GetData(new[] {new NxPage {Top = 0, Height = 20, Left = 1, Width = 1}});

Example: We can also use the current page and move to a relative position. In this case, move one column to the right.

            myListboxPager.MoveCurrentPages(pages => pages.Select(page =>
            {
            	page.Left = page.Left + 1;
            	return page;
            }));

Functions for moving pages

The Pager class provides a number of convenience functions for moving pages.

Example: Move the page manually

            myListbox.MovePage(currentPages => new[] { new NxPage { Top = 0, Height = 20 } });

You can then move to a relative position compared to the current page using the Pager class

Example: Move to the next page

            myListboxPager.MoveCurrentPages(Pager.Next);

Example: Move to the previous page

            myListboxPager.MoveCurrentPages(Pager.Previous);

Example: Move to the first page

            myListboxPager.MoveCurrentPages(Pager.First);

Example: Move to the last page

            myListboxPager.MoveCurrentPages(currentPages => Pager.Last(currentPages, myListbox.Size.cy));

Moving the page implicitly

You can move the page implicitly by retrieving the next page of data using the GetData, GetFirstPage, GetNextPage, GetPreviousPage and GetLastPage methods.

Example: Retrieve data from the current page

            IEnumerable<NxDataPage> currentListboxData = myListboxPager.GetData();

Example: Get the first page

            IEnumerable<NxDataPage> firstDataPages = myListboxPager.GetFirstPage();

Example: Get the next page

            IEnumerable<NxDataPage> nextDataPages = myListboxPager.GetNextPage();

Example: Get the previous page

            IEnumerable<NxDataPage> previousDataPages = myListboxPager.GetPreviousPage();

Example: Get the last page

            IEnumerable<NxDataPage> lastDataPages = myListboxPager.GetLastPage();

Example: Iterate across all pages using the Pager.Next method

            IEnumerable<IEnumerable<NxDataPage>> allDataPagesNext = myListboxPager.IteratePages(new[] {first10ElementsPage}, Pager.Next);

Example: Iterate across one column at a time from left to right

Essentially reading the table like a book from left to right before going to the next row. The number of columns is for this examples assumed to be 10.

	     var startPages = new[] { new NxPage { Top = 0, Left = 0, Width = 1, Height = myListbox.Size.cy } };
	     Func <IEnumerable<NxPage>, IEnumerable<NxPage>> myPager = pages => pages.Select(page =>
	     {
		   page.Left = page.Left + 1;
		   return page;
	     });
	     IEnumerable<IEnumerable<NxDataPage>> allDataPagesCustom = myListboxPager.IteratePages(startPages, myPager);