Question

我在特定日期获得空字符串，即13/03/2013。这是我的代码：

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"MM/dd/yyyy HH:mm:ss a"];
NSDate *myDate = [formatter dateFromString:@"12/03/2013 5:47:00 AM"];
NSDate *myDate1 = [formatter dateFromString:@"13/03/2013 6:25:48 AM"];           

NSDateFormatter *df = [[NSDateFormatter alloc] init];
[df setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"]];
[df setDateFormat:@"yyyy-MM-dd HH:mm"];
NSString *datestr = [df stringFromDate:myDate];
NSString *datestr1 = [df stringFromDate:myDate1];
NSLog(@"date object %@,%@",datestr,datestr1);

Answer 1

问题是您的日期格式为MM/dd/yyyy HH:mm:ss a。你添加了一个日期：13/03/2013 6:25:48 AM。

只有12个月，没有13个月。

将格式更改为：dd/MM/yyyy HH:mm:ss a

Answer 2

如果你看一下日期格式的标准会更好。 Date and Time Formats

    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"dd/MM/yyyy hh:mm:ss a"];
    NSDate *myDate = [formatter dateFromString:@"12/03/2013 5:47:00 AM"];
    NSDate *myDate1 = [formatter dateFromString:@"13/03/2013 6:25:48 AM"];  

    [formatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"]];
    [formatter setDateFormat:@"yyyy-MM-dd HH:mm"];
    NSString *datestr = [formatter stringFromDate:myDate];
    NSString *datestr1 = [formatter stringFromDate:myDate1];
    NSLog(@"date object %@,%@",datestr,datestr1);

Answer 3

因为没有第13个月。

13/03/2013是无效日期，因为您使用格式化程序作为MM / dd // yyyy。

试试这个

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"dd/MM/yyyy HH:mm:ss a"];
NSDate *myDate = [formatter dateFromString:@"12/03/2013 5:47:00 AM"];
NSDate *myDate1 = [formatter dateFromString:@"13/03/2013 6:25:48 AM"];

NSLog(@"%@",myDate1);


NSDateFormatter *df = [[NSDateFormatter alloc] init];
[df setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"]];
[df setDateFormat:@"yyyy-MM-dd HH:mm"];
NSString *datestr = [df stringFromDate:myDate];
NSString *datestr1 = [df stringFromDate:myDate1];



NSLog(@"date object %@,%@",datestr,datestr1);

NSDate在特定日期为空

3 个答案: