How do I tell the DataPager the number of complete records in the DataSource in a custom paging?

The default paging engine should have all of the request content to be called every time the ListView is displayed so that it can correctly determine how many pages can be paged into data.

Basically, he needs to know how many records we are looking at.

Thus, when using custom paging, we will only return the records that should appear on the current page of the viewed data; however, we will also need to tell the DataPager the number of complete records in the DataSource from which the query, consisting of.

How do we do it?

thank