iphone SDK:如何实现模态日期选择器？

Question

如何实现模态日期选择器？

我想要发生的是当用户输入文本字段时,会创建一个包含日期选择器的新视图.从那里,用户可以交互并选择日期.当视图关闭时,它应该以某种方式将日期返回给它的调用者.这可能吗？

顺便说一句,由于空间的原因,我无法将日期选择器放在我的主窗体上.

提前致谢.

Answer 1

使用代表!

标题:

@class DatePickerController;
@protocol DatePickerControllerDelegate
- (void) datePickerController:(DatePickerController *)controller didPickDate:(NSDate *)date;
@end

@interface DatePickerController : UIViewController {
  UIDatePicker *datePicker;
  NSObject <DatePickerControllerDelegate> *delegate;
}

@property (nonatomic, retain) UIDatePicker *datePicker;
@property (nonatomic, assign) NSObject <DatePickerControllerDelegate> *delegate;
@end

类:

@implementation DatePickerController
- (void) loadView {
  self.view = [[[UIView alloc] init] autorelease];
  self.datePicker = [[[UIDatePicker alloc] init] autorelease];
  [self.view addSubview:self.datePicker];
  UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
  [button setTitle:@"Done" forState:UIControlStateNormal];
  button.center = CGPointMake(160,240);
  [button addTarget:self action:@selector(done) forControlEvents:(UIControlEventTouchUpInside)];
  [self.view addSubview:button];
}

- (void) done {
  [delegate datePickerController:self didPickDate:datePicker.date];
}

- (void) dealloc {
  [datePicker release];
  [super dealloc];
}

@end

如果您愿意,可以使用NIB替换loadView中的所有垃圾.只需确保将datePicker声明为IBOutlet.当你想要实际使用它时:

- (void) pickDate {
  DatePickerController *screen = [[[DatePickerController alloc] init] autorelease];
  screen.delegate = self;
  [self presentModalViewController:screen animated:YES];
}

- (void) datePickerController:(DatePickerController *)controller didPickDate:(NSDate *)date {
  [self doSomethingWithDate:date];
  [controller dismissModalViewControllerAnimated:YES];
}