UIDatePicker 和 NSDate

Question

我有一个从 UIDatepicker 获得的 NSDate。

IBOutlet UIDatePicker *dueDate;
NSDate *selectedDate = [dueDate date];

如何以 int 的形式从 dueDate 检索月份？ （1 月为 1 月，2 月为 2 月，依此类推）

Answer 1

NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:NSMonthCalendarUnit fromDate:[dueDate date]];
NSInteger month = [components month];

Answer 2

使用 -[NSCalendar Components:fromDate:] 例如这里的示例：

http://developer.apple.com/iphone/library/documentation/Cocoa/Reference/Foundation/Classes/NSCalendar_Class/Reference/NSCalendar.html

Answer 3

NSDateFormatter *dateFormat = [[[NSDateFormatter alloc] initWithDateFormat:@"%m" allowNaturalLanguage:NO] autorelease];
int month = [[dateFormat stringFromDate:dueDate] intValue];