iphone - 如何让 UIDatePicker 显示用户选择的时间

Question

我有一个 UIDatepicker，让用户选择 time 。 UITableview在 UIView点击一个 UIButton UIDdatePicker出现，当用户选择时间并按返回按钮关闭时 UIDdatePicker查看，如果他想查看他在 UIDdatePicker 中选择的时间是什么时候. UIDdatePicker不显示用户选择的时间它显示当前时间或 datepicker 的时间开始时间。 我想在用户再次打开日期选择器时显示用户选择的时间。
这是我在用户按下 UIButton 时的代码显示 UIDdatePicker看法

-(IBAction)settingsButtonChanged:(UIButton *)sender
{

    userTimePicker = [[UIDatePicker alloc]init];
    [userTimePicker addTarget: self
                       action: @selector(userTimePickerValueChanged:)forControlEvents: UIControlEventValueChanged];
}

这是我的代码，它让日期选择器具有自定义时间限制

-(IBAction)datepickerTimenButtonChanged:(UIButton *)control
{

    if (control.tag == 1)
    {
        self.selectedButton = control.tag;

        int startTime = 7;
        int endTime = 11;

        NSDate *date1 = [NSDate date];
        components = [gregorian components: NSUIntegerMax fromDate: date1];

        [components setHour:startTime];;
        [components setMinute:00];

        NSDate *startDate = [gregorian dateFromComponents:components];

        [components setHour:endTime];
        [components setMinute:00];

        NSDate *endDate = [gregorian dateFromComponents:components];

        morningButton.selected = YES;
        afternoonButton.selected = NO;
        eveningButton.selected = NO;
        nightButton.selected = NO;

        [userTimePicker setDatePickerMode:UIDatePickerModeTime];

        [userTimePicker setMinimumDate:startDate];
        [userTimePicker setMaximumDate:endDate];

        [userTimePicker setDate:startDate animated:YES];
        [userTimePicker reloadInputViews];

    }

    if (control.tag == 2)
    {
        self.selectedButton = control.tag;

        morningButton.selected = NO;
        afternoonButton.selected = YES;
        eveningButton.selected = NO;
        nightButton.selected = NO;

        int startTime = 12;
        int endTime = 15;

        NSDate *date1 = [NSDate date];
        components = [gregorian components: NSUIntegerMax fromDate: date1];

        [components setHour:startTime];
        [components setMinute:00];

        NSDate *startDate = [gregorian dateFromComponents:components];

        [components setHour:endTime];
        [components setMinute:00];

        NSDate *endDate = [gregorian dateFromComponents:components];

        [userTimePicker setDatePickerMode:UIDatePickerModeTime];

        [userTimePicker setMinimumDate:startDate];
        [userTimePicker setMaximumDate:endDate];

        [userTimePicker setDate:startDate animated:YES];
        [userTimePicker reloadInputViews];

    }
}

允许用户选择自己时间的代码

-(void) userTimePickerValueChanged:(UIButton *)sender
{

    switch (self.selectedButton)
    {
        case 1:
        {
            NSUserDefaults *userSelectedMorningTime = [NSUserDefaults standardUserDefaults];

            NSDate *selectedMorningTime = [userTimePicker date];

            NSLog (@"SETTING: morningTimeKey");

            storedMornTime = selectedMorningTime;

            [userSelectedMorningTime setObject:selectedMorningTime forKey:@"morningTimeKey"];
            [userSelectedMorningTime synchronize];
        }
            break;

        case 2:
        {
            NSUserDefaults *userSelectedAfternoonTime = [NSUserDefaults standardUserDefaults];

            NSDate *selectedAfternoonTime = [userTimePicker date];

            NSLog (@"SETTING: afternoonTimeKey");

            storedAfternoonTime = selectedAfternoonTime;

            [userSelectedAfternoonTime setObject:selectedAfternoonTime forKey:@"afternoonTimeKey"];
            [userSelectedAfternoonTime synchronize];
        }
            break;
}

Answer 1

从我从代码中可以看出，您将所选时间保存到 NSUserDefaults ，但您永远不会使用从中节省的时间。

我的猜测是，如果你改变一切都应该有效。

-(IBAction)datepickerTimenButtonChanged:(UIButton *)control
{
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    if (control.tag == 1)
    {
        self.selectedButton = control.tag;

        int startTime = 7;
        int endTime = 11;

        //Saved Morning time date from user defaults
        NSDate *date1  = [defaults objectForKey:@"morningTimeKey"];
        if(!date1) date1 = [NSDate date];
        components = [gregorian components: NSUIntegerMax fromDate: date1];

        [components setHour:startTime];;
        [components setMinute:00];

        NSDate *startDate = [gregorian dateFromComponents:components];

        [components setHour:endTime];
        [components setMinute:00];

        NSDate *endDate = [gregorian dateFromComponents:components];

        morningButton.selected = YES;
        afternoonButton.selected = NO;
        eveningButton.selected = NO;
        nightButton.selected = NO;

        [userTimePicker setDatePickerMode:UIDatePickerModeTime];

        [userTimePicker setMinimumDate:startDate];
        [userTimePicker setMaximumDate:endDate];

        [userTimePicker setDate:startDate animated:YES];
        [userTimePicker reloadInputViews];

    }

    if (control.tag == 2)
    {
        self.selectedButton = control.tag;

        morningButton.selected = NO;
        afternoonButton.selected = YES;
        eveningButton.selected = NO;
        nightButton.selected = NO;

        int startTime = 12;
        int endTime = 15;

        //Saved AfterNoon time date from user defaults
        NSDate *date1  = [defaults objectForKey:@"afternoonTimeKey"];
        if(!date1) date1 = [NSDate date];

        components = [gregorian components: NSUIntegerMax fromDate: date1];

        [components setHour:startTime];
        [components setMinute:00];

        NSDate *startDate = [gregorian dateFromComponents:components];

        [components setHour:endTime];
        [components setMinute:00];

        NSDate *endDate = [gregorian dateFromComponents:components];

        [userTimePicker setDatePickerMode:UIDatePickerModeTime];

        [userTimePicker setMinimumDate:startDate];
        [userTimePicker setMaximumDate:endDate];

        [userTimePicker setDate:startDate animated:YES];
        [userTimePicker reloadInputViews];

    }
}