Question

我的dateString格式为"mm/dd/yyyy '-' HH:mm"。我想以字符串中的字符串和小时提取日期。我尝试过以下代码，但这会返回错误的日期：

- (void) extractDate: (NSString *)dateString intoHour: (NSString *)hourLabel and: (NSString*)dateLabel {
    NSDateFormatter *formatter=[[NSDateFormatter alloc]init];
    [formatter setDateFormat:@"mm/dd/yyyy '-' HH:mm"];
    NSData *date = [formatter dateFromString:dateString];

    NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear | NSHourCalendarUnit | NSMinuteCalendarUnit fromDate:date];

    hourLabel = [NSString stringWithFormat:@"%lu:%lu", [components hour], [components minute]];
    dateLabel = [NSString stringWithFormat:@"%lu/%lu/%lu", [components day], [components month], [components year]];
}

例如字符串："05/01/2015 - 11:15"

结果：日期：1/1/2015，时间：11:15 以及如何维护此日期格式dd/mm/yyyy，我的意思是当这一天为1时，它会显示01

Answer 1

未经测试但是：

本月

MM。不是mm，而是分钟。

您已经有NSDateFormatter，为什么不再使用它而不是NSDateComponents和NSString格式？

NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
[formatter setDateFormat:@"MM/dd/yyyy '-' HH:mm"];
NSDate *date = [formatter dateFromString:dateString];

//Now you have the correct date. So we'll use the NSDateFormatter to transform NSDate (date) into NSString according to the format we need.

[formatter setDateFormat:@"MM/dd/yyyy"];
dateLabel = [formatter stringFromDate:date];
[formatter setDateFormat:@"HH:mm"];
hourLabel = [formatter stringFromDate:date];

hourLabel / dateLabel作为NSString而非UILabel是一个误导性的变种命名。

从NSDate中提取日期和小时 - 目标C.

1 个答案: