改变self.editButtonItem.title

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    self.editButtonItem.possibleTitles = [NSSet setWithObjects:@"编辑", @"完成", nil];
    self.editButtonItem.title = @"编辑";
    self.navigationItem.leftBarButtonItem = self.editButtonItem;
}

- (void)setEditing:(BOOL)editing 
          animated:(BOOL)animated
{
    [super setEditing:editing animated:animated];
    
    if (self.editing) {
        self.editButtonItem.title = @"完成";
    } else {
        self.editButtonItem.title = @"编辑";
    }
}

possibleTitles
The set of possible titles to display on the bar button.

@property(nonatomic, copy) NSSet *possibleTitles
Discussion
Use this property to provide a hint to the system on how to correctly size the bar button item to be wide enough to accommodate your widest title. Set the value of this property to an NSSet object containing all the titles you intend as possible titles for the bar button item. Use the actual text strings you intend to display.

This property applies to bar button items placed on navigation bars or toolbars.

Availability
Available in iOS 2.0 and later.
Related Sample Code
AccelerometerGraph
Declared In
UIBarButtonItem.h

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