转换时间戳

Question

我找不到这个问题的解决方案，我正在从firebase获取数据，其中一个字段是时间戳，看起来像这样-

Swift示例（作品）：

func readTimestamp(timestamp: Int) {
    let now = Date()
    let dateFormatter = DateFormatter()
    let date = Date(timeIntervalSince1970: Double(timestamp))
    let components = Set<Calendar.Component>([.second, .minute, .hour, .day, .weekOfMonth])
    let diff = Calendar.current.dateComponents(components, from: date, to: now)
    var timeText = ""

    dateFormatter.locale = .current
    dateFormatter.dateFormat = "HH:mm a"

    if diff.second! <= 0 || diff.second! > 0 && diff.minute! == 0 || diff.minute! > 0 && diff.hour! == 0 || diff.hour! > 0 && diff.day! == 0 {
        timeText = dateFormatter.string(from: date)
    }
    if diff.day! > 0 && diff.weekOfMonth! == 0 {
        timeText = (diff.day == 1) ? "\(diff.day!) DAY AGO" : "\(diff.day!) DAYS AGO"
    }
    if diff.weekOfMonth! > 0 {
        timeText = (diff.weekOfMonth == 1) ? "\(diff.weekOfMonth!) WEEK AGO" : "\(diff.weekOfMonth!) WEEKS AGO"
    }

    return timeText
}

我的飞镖尝试:

String readTimestamp(int timestamp) {
    var now = new DateTime.now();
    var format = new DateFormat('HH:mm a');
    var date = new DateTime.fromMicrosecondsSinceEpoch(timestamp);
    var diff = date.difference(now);
    var time = '';

    if (diff.inSeconds <= 0 || diff.inSeconds > 0 && diff.inMinutes == 0 || diff.inMinutes > 0 && diff.inHours == 0 || diff.inHours > 0 && diff.inDays == 0) {
      time = format.format(date); // Doesn't get called when it should be
    } else {
      time = diff.inDays.toString() + 'DAYS AGO'; // Gets call and it's wrong date
    }

    return time;
}

并且它返回的日期/时间是错误的。

更新:

String readTimestamp(int timestamp) {
    var now = new DateTime.now();
    var format = new DateFormat('HH:mm a');
    var date = new DateTime.fromMicrosecondsSinceEpoch(timestamp * 1000);
    var diff = date.difference(now);
    var time = '';

    if (diff.inSeconds <= 0 || diff.inSeconds > 0 && diff.inMinutes == 0 || diff.inMinutes > 0 && diff.inHours == 0 || diff.inHours > 0 && diff.inDays == 0) {
      time = format.format(date);
    } else {
      if (diff.inDays == 1) {
        time = diff.inDays.toString() + 'DAY AGO';
      } else {
        time = diff.inDays.toString() + 'DAYS AGO';
      }
    }

    return time;
  }

Answer 1

为任何需要的人提供完整代码:

String readTimestamp(int timestamp) {
    var now = DateTime.now();
    var format = DateFormat('HH:mm a');
    var date = DateTime.fromMillisecondsSinceEpoch(timestamp * 1000);
    var diff = now.difference(date);
    var time = '';

    if (diff.inSeconds <= 0 || diff.inSeconds > 0 && diff.inMinutes == 0 || diff.inMinutes > 0 && diff.inHours == 0 || diff.inHours > 0 && diff.inDays == 0) {
      time = format.format(date);
    } else if (diff.inDays > 0 && diff.inDays < 7) {
      if (diff.inDays == 1) {
        time = diff.inDays.toString() + ' DAY AGO';
      } else {
        time = diff.inDays.toString() + ' DAYS AGO';
      }
    } else {
      if (diff.inDays == 7) {
        time = (diff.inDays / 7).floor().toString() + ' WEEK AGO';
      } else {

        time = (diff.inDays / 7).floor().toString() + ' WEEKS AGO';
      }
    }

    return time;
  }

感谢亚历克斯·哈斯拉姆的帮助！

Answer 2

> < li>

从毫秒:

var millis = 978296400000;
var dt = DateTime.fromMillisecondsSinceEpoch(millis);

// 12 Hour format:
var d12 = DateFormat('MM/dd/yyyy, hh:mm a').format(dt); // 12/31/2000, 10:00 PM

// 24 Hour format:
var d24 = DateFormat('dd/MM/yyyy, HH:mm').format(dt); // 31/12/2000, 22:00

来自火神：

Map<String, dynamic> map = docSnapshot.data()!;
DateTime dt = (map['timestamp'] as Timestamp).toDate();

将一种格式转换为另一种格式:

>

12小时至24小时：

var input = DateFormat('MM/dd/yyyy, hh:mm a').parse('12/31/2000, 10:00 PM');
var output = DateFormat('dd/MM/yyyy, HH:mm').format(input); // 31/12/2000, 22:00

24小时至12小时:

var input = DateFormat('dd/MM/yyyy, HH:mm').parse('31/12/2000, 22:00');
var output = DateFormat('MM/dd/yyyy, hh:mm a').format(input); // 12/31/2000, 10:00 PM

_{使用国际包（用于格式化）}

Answer 3

您的时间戳格式实际上是以秒(Unix时间戳)为单位，而不是以微秒为单位。如果有，答案如下:

改变：

dart prettyprint-override">var date = new DateTime.fromMicrosecondsSinceEpoch(timestamp);

到

var date = DateTime.fromMillisecondsSinceEpoch(timestamp * 1000);