如何获得两个日期之间的天数objective-c

Question

我正在尝试制作一个标签,说明事件发生了多少天.我想计算今天的日期和事件日期之间的差异.我正在使用此代码,它给我-4600.它工作正常,直到我使用今天的日期.

NSDateFormatter *f = [[NSDateFormatter alloc] init];
    [f setDateFormat:@"yyyy-MM-dd"];
    NSDate *startDate = [NSDate date];
    NSDate *endDate = [f dateFromString:end];
    NSCalendar *gregorianCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
    NSDateComponents *components = [gregorianCalendar components:NSDayCalendarUnit
                                                        fromDate:startDate
                                                          toDate:endDate
                                                         options:0];
    return components.day;
return components.day;

Answer 1

默认情况下,[NSDate date]返回日期为like,2013-08-06 08:50:25 +0000 并且您已将格式化程序设置yyyy-MM-dd为此,因此您必须将startDate转换yyyy-MM-dd为此表单.

试试这个

NSDateFormatter *f = [[NSDateFormatter alloc] init];
    [f setDateFormat:@"yyyy-MM-ddHH:mm:ss ZZZ"];
    NSDate *startDate = [NSDate date];
    NSLog(@"%@",startDate);
    NSDate *endDate = [f dateFromString:end];
    NSLog(@"%@",endDate);


    NSCalendar *gregorianCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
    NSDateComponents *components = [gregorianCalendar components:NSDayCalendarUnit
                                                        fromDate:startDate
                                                          toDate:endDate
                                                         options:0];
    return components.day;