我正在比较两个日期,但是当我将这两个日期输入一个字符串变量时它起作用了,但是当我将这些值传递给数据比较方法时它不起作用,为什么?
这是我使用的代码吗?
NSString *dateString =@"2013-05-12 22:10:02";
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
// this is imporant - we set our input date format to match our input string
// if format doesn't match you'll get nil from your string, so be careful
[dateFormatter setDateFormat:@"yyyy-MM-dd HH:MM:SS"];
NSDate *dateFromString = [[NSDate alloc] init];
// voila!
dateFromString = [dateFormatter dateFromString:dateString];
NSString *dateString1 = @"2013-03-04 07:59:08";
NSDateFormatter *dateFormatter1 = [[NSDateFormatter alloc] init];
// this is imporant - we set our input date format to match our input string
// if format doesn't match you'll get nil from your string, so be careful
[dateFormatter1 setDateFormat:@"yyyy-MM-dd HH:MM:SS"];
NSDate *dateFromString1 = [[NSDate alloc] init];
// voila!
dateFromString1 = [dateFormatter dateFromString:dateString1];
if ([dateFromString compare:dateFromString1] == NSOrderedDescending)
{
NSLog(@"1 is later than 2");
} else if ([dateFromString compare:dateFromString1] == NSOrderedAscending)
{
NSLog(@"1 is earlier than 2");
} else
{
NSLog(@"dates are the same");
}
**当我将日期(nsstring 格式)传递给方法时
(int)compareDate:(NSString *)date1:(NSString *)date2
在那个方法中我写了上面的比较代码 所以我像这样调用这个方法
[self compareDate:date1:date2]
我总是得到“日期相同”的值????当我手动输入日期时,我得到了准确的答案??这是为什么?**
最佳答案
用以下代码替换您的代码。 “mm”格式用于分钟,“MM”用于月。并使用“ss”表示秒而不是“SS”。阅读苹果文档以获取有关日期格式化程序的详细信息。
NSString *dateString =@"2013-05-12 22:10:02";
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
// this is imporant - we set our input date format to match our input string
// if format doesn't match you'll get nil from your string, so be careful
[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
NSDate *dateFromString = [[NSDate alloc] init];
// voila!
dateFromString = [dateFormatter dateFromString:dateString];
NSString *dateString1 = @"2013-03-04 07:59:08";
NSDateFormatter *dateFormatter1 = [[NSDateFormatter alloc] init];
// this is imporant - we set our input date format to match our input string
// if format doesn't match you'll get nil from your string, so be careful
[dateFormatter1 setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
NSDate *dateFromString1 = [[NSDate alloc] init];
// voila!
dateFromString1 = [dateFormatter dateFromString:dateString1];
if ([dateFromString compare:dateFromString1] == NSOrderedDescending)
{
NSLog(@"1 is later than 2");
} else if ([dateFromString compare:dateFromString1] == NSOrderedAscending)
{
NSLog(@"1 is earlier than 2");
} else
{
NSLog(@"dates are the same");
}
关于ios - NSDate 比较显示错误的值?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/16933297/