ios - 使用 NSDateFormatter 将日期从一种格式更改为另一种格式

Question

如何将 NSDateFormatted 字符串 Apr 18, 2014 10:34:19 AM 转换为 2014-04-18T17:34:19？我试过下面的但它返回一个 nil NSDate 指针。这里的任何人都可以帮助我。谢谢。

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
[dateFormatter  setDateFormat:@"yyyy'-'MM'-'dd'T'HH':'mm':'ss"];
NSDate *date = [dateFormatter dateFromString:@"Apr 18, 2014 10:34:19 AM"];  // Error nil
NSLog(@"date: %@", date);

Answer 1

您需要使用 2 个日期格式化程序，一个用于解析另一个用于显示:

NSDateFormatter *parsingFormatter = [NSDateFormatter new];
[parsingFormatter setDateFormat:@"MMM dd, yyyy hh:mm:ss a"];
NSDate *date = [parsingFormatter dateFromString:@"Apr 18, 2014 10:34:19 AM"];
NSLog(@"date: %@", date);

NSDateFormatter *displayingFormatter = [NSDateFormatter new];
[displayingFormatter setDateFormat:@"yyyy'-'MM'-'dd'T'HH':'mm':'ss"];
NSString *display = [displayingFormatter stringFromDate:date];
NSLog(@"display: %@", display); // 2014-04-18T17:34:19