iOS UIBarButtonItem Action不适用于真实设备

Question

我以编程方式添加datePicker，其中包含带有完成按钮的工具栏 这是我的代码：

CGRect toolbarTargetFrame = CGRectMake(0, self.view.bounds.size.height-216-44, 320, 44);
CGRect datePickerTargetFrame = CGRectMake(0, self.view.bounds.size.height-216, 320, 216);

darkView = [[UIView alloc] initWithFrame:self.view.bounds];
darkView.alpha = 0;
darkView.backgroundColor = [UIColor blackColor];
darkView.tag = 9;
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(dismissDatePicker:)];
[darkView addGestureRecognizer:tapGesture];
[self.view addSubview:darkView];

datePicker = [[UIDatePicker alloc] initWithFrame:CGRectMake(0, self.view.bounds.size.height+44, 320, 216)];
datePicker.tag = 10;
datePicker.backgroundColor = [UIColor whiteColor];
[datePicker addTarget:self action:@selector(changeDate:) forControlEvents:UIControlEventValueChanged];
[self.view addSubview:datePicker];

toolBar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, self.view.bounds.size.height, 320, 44)];
toolBar.tag = 11;
toolBar.barStyle = UIBarStyleBlackTranslucent;
UIBarButtonItem *spacer = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];

UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(doneButtonPressed:)];
[toolBar setItems:[NSArray arrayWithObjects:spacer, doneButton, nil]];
[self.view addSubview:toolBar];

[UIView beginAnimations:@"MoveIn" context:nil];
toolBar.frame = toolbarTargetFrame;
datePicker.frame = datePickerTargetFrame;
darkView.alpha = 0.5;
[UIView commitAnimations];

问题是只在模拟器上调用了完成按钮动作，但在真实设备上没有， 有谁知道为什么？ 感谢