以下代码在 iOS 4.3 下显示奇怪的行为（也许其他版本也是如此）。在这个例子中，一个UIDatePicker其日期设置为4 Aug 2011 2:31 PM被展示。这UILabel以下UIDatePicker显示日期以供参考。他们三个UIButtons下面，标记为 1、5、10 设置minuteInterval on the UIDatePicker.
点击 1 - 显示所选日期UIDatePicker to be 4 Aug 2011 2:31 PM，分钟间隔为 1，这是预期的。
点击 5 - 显示所选日期UIDatePicker to be 4 Aug 2011 2:35 PM，分钟间隔为 5，这是预期的（有人可能会认为时间应该向下舍入，但这不是一个大问题）。
点击 10 - 显示所选日期UIDatePicker to be 4 Aug 2011 2:10 PM，分钟间隔为 10。好的，分钟间隔是正确的，但是选择的时间是 2:10？人们预计会是 2:40（如果向上舍入）或 2:30（如果向下舍入）。
BugDatePickerVC.h
#import <UIKit/UIKit.h>
@interface BugDatePickerVC : UIViewController {
NSDateFormatter *dateFormatter;
NSDate *date;
UIDatePicker *datePicker;
UILabel *dateL;
UIButton *oneB;
UIButton *fiveB;
UIButton *tenB;
}
- (void) buttonEventTouchDown:(id)sender;
@end
BugDatePickerVC.m
导入“BugDatePickerVC.h”
@implementation BugDatePickerVC
- (id) init
{
if ( !(self = [super init]) )
{
return self;
}
dateFormatter = [[NSDateFormatter alloc] init];
dateFormatter.dateFormat = @"d MMM yyyy h:mm a";
date = [[dateFormatter dateFromString:@"4 Aug 2011 2:31 PM"] retain];
// = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
// Date picker
datePicker = [[UIDatePicker alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 320.0f, 216.0f)];
datePicker.date = date;
datePicker.minuteInterval = 1;
[self.view addSubview:datePicker];
// = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
// Label with the date.
dateL = [[UILabel alloc] initWithFrame:CGRectMake(10.0f, 230.0f, 300.0f, 32.0f)];
dateL.text = [dateFormatter stringFromDate:date];
[self.view addSubview:dateL];
// = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
// Button that set the date picker's minute interval to 1.
oneB = [UIButton buttonWithType:UIButtonTypeRoundedRect];
oneB.frame = CGRectMake(10.0f, 270.0f, 100.0f, 32.0f);
oneB.tag = 1;
[oneB setTitle:@"1" forState:UIControlStateNormal];
[oneB addTarget:self
action:@selector(buttonEventTouchDown:)
forControlEvents:UIControlEventTouchDown];
[self.view addSubview:oneB];
// = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
// Button that set the date picker's minute interval to 5.
fiveB = [UIButton buttonWithType:UIButtonTypeRoundedRect];
fiveB.frame = CGRectMake(10.0f, 310.0f, 100.0f, 32.0f);
fiveB.tag = 5;
[fiveB setTitle:@"5" forState:UIControlStateNormal];
[fiveB addTarget:self
action:@selector(buttonEventTouchDown:)
forControlEvents:UIControlEventTouchDown];
[self.view addSubview:fiveB];
// = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
// Button that set the date picker's minute interval to 10.
tenB = [UIButton buttonWithType:UIButtonTypeRoundedRect];
tenB.frame = CGRectMake(10.0f, 350.0f, 100.0f, 32.0f);
tenB.tag = 10;
[tenB setTitle:@"10" forState:UIControlStateNormal];
[tenB addTarget:self
action:@selector(buttonEventTouchDown:)
forControlEvents:UIControlEventTouchDown];
[self.view addSubview:tenB];
return self;
}
- (void) dealloc
{
[dateFormatter release];
[date release];
[datePicker release];
[dateL release];
[oneB release];
[fiveB release];
[tenB release];
[super dealloc];
}
- (void) buttonEventTouchDown:(id)sender
{
datePicker.minuteInterval = [sender tag];
}
