我正在使用这段代码在 ViewControllerA
中推送一个 View Controller :
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];
在滑入的DatePickerViewController
中,它有一个文本字段。在 ViewControllerA
中,一旦触发了 viewWillDisappear
方法,我如何获取此文本字段的值,这是为了保存数据。
最佳答案
有几种方法可以做到这一点。最好是使用委托(delegate)模式或通知系统。
你选择哪一个取决于你的愿望。如果您只是想让“父 Controller ”知道该值,请使用委托(delegate)方法。
使用委托(delegate)或通知创建松耦合结构并使可重用类成为可能。
编辑:一些示例代码。当心:未经测试且来 self 的脑海!
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];
}
ViewControllerA.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
}
关于ios - 如何访问父 View Controller ?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/2760679/