我还发现我无法使用 self.itemButton.title = @"Changed Title这样的方法在代码中更改此按钮的标题; ，但是我通过在两个按钮之间切换来解决了这个问题.

I've also found out that I cannot change the title of this button in code with method like self.itemButton.title = @"Changed Title";, but I solved this by switching between two buttons.

- (IBAction)editAction:(id)sender {
    [self.toolBar setItems:@[self.doneButton]];
}

- (IBAction)doneAction:(id)sender {
    [self.toolBar setItems:@[self.editButton]];
}

更新:

此问题已在Xcode 6.2中解决.

This issue has been resolved in Xcode 6.2.