iOS 5 Programming Cookbook

3.11. Moving Cells and Sections in Table Views

Problem

You want to move and shuffle cells and sections inside a table view, with smooth and intuitive animations.

Solution

Use the moveSection:toSection: method of the table view to move a section to a new position. You can also use the moveRowAtIndexPath:toIndexPath: method to move a table view cell from its current place to a new place.

Discussion

Moving table view cells and sections differs from exchanging them. Let’s have a look at an example that will make this easier to understand. Let’s say you have three sections in your table view: Sections A, B, and C. If you move Section A to Section C, the table view will notice this move and will then shift Section B to the previous position of Section A, and will move Section B to the previous position of Section B. However, if Section B is moved to Section C, the table view will not have to move Section A at all, as it is sitting on top and doesn’t interfere with the repositioning of Section B and C. In this case, Section B will be moved to Section C and Section C to Section B. The same logic will be used by the table view when moving cells.

To demonstrate this, let’s create a table view and preload it with three sections, each of which contains three cells of its own. Let’s start with the header file of our view controller:

#import <UIKit/UIKit.h> @interface Moving_Cells_and_Sections_in_Table_ViewsViewController : UIViewController <UITableViewDelegate, UITableViewDataSource> @property (nonatomic, ...