我正在构建一个iOS应用程序，它利用本地通知来提醒用户完成任务，但仅限于特定日期（由用户选择） . 通知应该触发的时间由日期选择器设置 . 我的代码基于另一个SO帖子中的一些代码 .

假设用户希望在周日完成所述任务 . 我要做的第一件事是找出当前日期是什么，并从中获取正确的组件，然后从日期选择器获取正确的组件，包括小时和分钟 .

//set up calendar and correct components
NSDate *now = [NSDate date];
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitWeekOfYear|NSCalendarUnitWeekday|NSCalendarUnitHour|NSCalendarUnitMinute fromDate:now]; //get the required calendar units
NSDateComponents *pickedComponents = [calendar components:(NSCalendarUnitHour | NSCalendarUnitMinute) fromDate:picker.date];

NSDate *minuteHour = [calendar dateFromComponents:pickedComponents];
[[NSUserDefaults standardUserDefaults] setObject:minuteHour forKey:@"FireTime"];

NSString *reminder = @"Don't forget to check which customers are on vacation!";

接下来，保存数据，并设置通知 . 此代码对于一周中的每一天都是相同的，只更改了日期名称 .

当tempStatus等于“1”时，用户选择该日作为一天来提醒他们 .

//Save data
//sunday
UILocalNotification *localNotification = [[UILocalNotification alloc] init];
if ([sundayTempStatus isEqual:@"1"])
{
    //permanently save the status
    [[NSUserDefaults standardUserDefaults] setObject:@"1" forKey:@"Sunday"];

    //set up notifications
    //if it is past sunday, push next week
    if (components.weekday > 1)
    {
        components.weekOfYear++; //if already passed sunday, make it next sunday
    }

    components.hour = [pickedComponents hour];
    components.minute = [pickedComponents minute];

    NSDate *fireDate = [calendar dateFromComponents:components];

    localNotification.fireDate = fireDate;
    localNotification.alertBody = reminder;
    localNotification.timeZone = [NSTimeZone systemTimeZone];
    localNotification.repeatInterval = NSCalendarUnitWeekOfYear;
    [[UIApplication sharedApplication] scheduleLocalNotification:localNotification];
}
else
{
    [[NSUserDefaults standardUserDefaults] setObject:@"0" forKey:@"Sunday"];
}

在此先感谢，如有必要，我很乐意提供更多信息和代码 .

ios objective-c date notifications uilocalnotification