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我正在使用此代码将视图控制器推入ViewControllerA：

DatePickerViewController *viewController = [[DatePickerViewController alloc] initWithNibName:@"DatePickerViewController" bundle:nil];
NSMutableArray *info = [[NSMutableArray alloc] initWithObjects:@"Exam Duration",nil];
[viewController setInfo:info];
[info release];
[self.navigationController pushViewController:viewController animated:YES];
[viewController release];

在DatePickerViewController滑入的那个中，它有一个文本字段。一旦触发ViewControllerA该方法，如何获取此文本字段的值，这是为了保存数据。viewWillDisappear

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1 回答 1

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有几种方法可以做到这一点。最好的办法是使用委托模式或通知系统。

你选择哪一个取决于你的愿望。如果您只想让“父控制器”知道该值，请使用委托方法。

使用委托或通知会创建一个松散耦合的结构并使可重用类成为可能。

编辑：一些示例代码。当心：未经测试，从我的头顶！

DatePickerViewController.h

@protocol DatePickerViewControllerDelegate
    -(void)datePicker:(DatePickerViewController *)picker pickedDate:(NSDate *)date;
@end

DatePickerViewController.m

- (void)viewWillDisappear:(BOOL)animated {
    [self.delegate datePicker:self pickedDate:theDate]; //Delegate is an ivar
    [super viewWillDisappear:animated];
}

视图控制器A.m

//
DatePickerViewController *viewController = [[DatePickerViewController alloc] initWithNibName:@"DatePickerViewController" bundle:nil];
NSMutableArray *info = [[NSMutableArray alloc] initWithObjects:@"Exam Duration",nil];
[viewController setInfo:info];
[info release];
[viewController setDelegate:self]; // Set the delegate of the date picker
[self.navigationController pushViewController:viewController animated:YES];
[viewController release];
//

-(void)datePicker:(DatePickerViewController *)picker pickedDate:(NSDate *)date; {
     //Deal with the new date here
}
于 2010-05-03T19:43:32.997 回答