Question

我有一个日期选择器和2个按钮。我想在单击按钮时以编程方式设置datepicker值。就像当我按下第一个按钮时，datepicker值变为今天的日期和00:00:00：时间，当我按下第二个按钮时，datepicker值变为今天的日期和23:59:59时间。

怎么做？

Answer 1

简单的任务，假设您已经添加了两个按钮按下时调用的函数，你需要这样的东西：

-(IBAction)beginPressed:(id)sender
{
  NSDate * now = [[NSDate alloc] init];
  NSCalendar *cal = [NSCalendar currentCalendar];
  NSDateComponents * comps = [cal components:NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit fromDate:now];
  [comps setHour:0];
  [comps setMinute:0];
  [comps setSecond:0];
  NSDate * date = [cal dateFromComponents:comps];
  [self.datePicker setDate:date animated:TRUE];

}
-(IBAction)endPressed:(id)sender
{
  NSDate * now = [[NSDate alloc] init];
  NSCalendar *cal = [NSCalendar currentCalendar];
  NSDateComponents * comps = [cal components:NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit fromDate:now];
  [comps setHour:23];
  [comps setMinute:59];
  [comps setSecond:59];
  NSDate * date = [cal dateFromComponents:comps];
  [self.datePicker setDate:date animated:TRUE];
}

我认为设置组件的部分并不清楚，检查上述类的API，你会发现更多。

修改：我已将日历更改为当前默认日历并立即初始化日历。

Answer 2

NSDateFormatter *dateFormat;
  dateFormat = [[NSDateFormatter alloc] init];
 [dateFormat setDateFormat:@"h:mm a"];
  NSDate *exampleDateFromString =[dateFormat dateFromString:@"8:48 AM"]; 
  date-picker.minimumDate=exampleDateFromString;
 [date-picker setDate:exampleDateFromString];

Answer 3

对于那些想知道如何在Swift中执行此操作的人：

let now = NSDate()
let cal = NSCalendar.currentCalendar()
let comp = cal.components([.Year, .Month, .Day], fromDate: now)
comp.hour = 0 // or whatever you need
comp.minute = 0
let date = cal.dateFromComponents(comp)!
picker.setDate(date, animated: true)

以编程方式设置UIDatepicker

3 个答案: