Extract date from UIDatePicker

问题:

Can u please tell me how to extract a date from UIDatePicker, i have extracted the month but i am not able to extract the date,Please help me out

Thank You

回答1:

The NSDate object can be extracted by just accessing the date property of the object:

NSDate *dateFromPicker = [someDatePicker date];  

If you want to extract detailed information about what month, day and year a person has chosen, this is a little bit more complex (but just a little bit). The solution is to use an NSCalendar reference - it is likely that you'd want to use Gregorian.

NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier: NSGregorianCalendar];

Now you should use an unsigned integer unit flags to specify which units you want to extract from a date (i.e. day, day-of-the-month, year, era etc.). Use a bitwise | to select multiple unit flags:

unsigned unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit;

Now create a date components object:

NSDateComponents *components = [calendar components: unitFlags fromDate: dateFromPicker];

From this components date, you can now extract integer values of what you have mentioned in the unitFlags integer:

int year = [components year];
int month = [components month];

All other properties (i.e. day, day-of-the-month, era etc.) are undefined in such a components object - remember, you can only extract what you've explicitly said you want to extract.

Finally, free the calendar object to avoid memory leaks:

[calendar release];

Hope this helps. For more information, see Apple reference: http://developer.apple.com/library/ios/#documentation/Cocoa/Conceptual/DatesAndTimes/DatesAndTimes.html

回答2:

You can access the date property of the UIDatePicker class to get the date!