flutter - 无法从格式化的DateString解析 “CET”

Question

为什么DateFormat解析器无法解析CET？

final String dateString = "Sat Jul 05 00:00:00 CET 1975";
final DateTime dateTime =
    DateFormat("EEE MMM dd HH:mm:ss vvv yyyy").parse(dateString);

结果是

FormatException: Trying to read from Sat Jul 05 00:00:00 CET 1975 at position 21

如果我算对的话，位置21将为“C”。

有人遇到过这个问题吗？

Answer 1

intl包尚未实现解析时区，如 date_format_field 类所示:

      case 'v':
        return formatTimeZoneId(date);
      case 'z':
        return formatTimeZone(date);
      case 'Z':
        return formatTimeZoneRFC(date);

当您查看这些函数的实现时:

  String formatTimeZoneId(DateTime date) {
    // TODO(alanknight): implement time zone support
    throw new UnimplementedError();
  }

  String formatTimeZone(DateTime date) {
    throw new UnimplementedError();
  }

  String formatTimeZoneRFC(DateTime date) {
    throw new UnimplementedError();
  }

这个 issue 自2015年以来一直开放，这是对此负责的人之一的回应:

We don't expect to implement those until Dart DateTime's have time zone information, and that's not planned. I wouldn't expect it unless/until JavaScript DateTime's have them. Including localized TimeZone names is a lot of data. We should probably just remove those APIs until such time as we actually provide them.