Asks the delegate for the estimated height of a row in a specified location.
- iOS 7.0+
- Mac Catalyst 13.0+
- tvOS 9.0+
The table-view object requesting this information.
An index path that locates a row in
A nonnegative floating-point value that estimates the height (in points) that
row should be. Return
automatic if you have no estimate.
Providing an estimate the height of rows can improve the user experience when loading the table view. If the table contains variable height rows, it might be expensive to calculate all their heights and so lead to a longer load time. Using estimation allows you to defer some of the cost of geometry calculation from load time to scrolling time.