iOS 5 Programming Cookbook

2.4. Picking the Date and Time with UIDatePicker

Problem

You want to allow the users of your app to select a date and time using an intuitive and ready-made user interface.

Solution

Use the UIDatePicker class.

Discussion

UIDatePicker is very similar to the UIPickerView class. The date picker is in fact a prepopulated picker view. A good example of the date picker control is in the Calendar app on the iPhone (Figure 2-14).

Figure 2-14. A date picker shown at the bottom of the screen

Let’s get started by first declaring a property of type UIDatePicker and then allocating and initializing this property and adding it to the view of our view controller:

#import <UIKit/UIKit.h>

@interface Picking_Date_and_Time_with_UIDatePickerViewController
           : UIViewController

@property (nonatomic, strong) UIDatePicker *myDatePicker;

@end

Let’s synthesize the property now:

#import "Picking_Date_and_Time_with_UIDatePickerViewController.h"

@implementation Picking_Date_and_Time_with_UIDatePickerViewController

@synthesize myDatePicker;

...

And now let’s instantiate the date picker, as planned:

- (void)viewDidLoad{
  [super viewDidLoad];
  self.view.backgroundColor = [UIColor whiteColor];
  self.myDatePicker = [[UIDatePicker alloc] init];
  self.myDatePicker.center = self.view.center;
  [self.view addSubview:self.myDatePicker];
}

Now let’s run the app and see how it looks, in Figure 2-15.

Figure 2-15. A simple date picker

You can see ...