Flutter 日期时间转换为字符串

/*  时间戳转字符串
* timestamp 时间戳
* formart ："y-m":年和月之间的符号,
* "m-d":月和日之间的符号
* "h-m":时和分之间的符号,
* "m-s":分和秒之间的符号；
* "m-a":是否显示上午和下午
*/

 static String dateAndTimeToString(var timestamp, {Map formart}) {
   if (timestamp == null || timestamp == "") {
     return "";
   }
   String targetString = "";
   final date = new DateTime.fromMicrosecondsSinceEpoch(timestamp * 1000);
   // final String tmp = date.toString();
   String year = date.year.toString();
   String month = date.month.toString();
   if(date.month<=9){
     month = "0" + month;
   }
   String day = date.day.toString();
   if(date.day<=9){
     day = "0" + day;
   }
   String hour = date.hour.toString();
   if(date.hour<=9){
     hour = "0" + hour;
   }
   String minute = date.minute.toString();
   if(date.minute<=9){
     minute = "0" + minute;
   }
   String second = date.second.toString();
   if(date.second<=9){
     second = "0" + second;
   }
   // String millisecond = date.millisecond.toString();
   String morningOrafternoon = "上午";
   if(date.hour >= 12){
     morningOrafternoon = "下午";
   }
   
   if(formart["y-m"] != null && formart["m-d"] != null){
     targetString = year + formart["y-m"] + month + formart["m-d"] + day;
   }else if(formart["y-m"] == null && formart["m-d"] != null){
     targetString = month + formart["m-d"] + day;
   }else if(formart["y-m"] != null && formart["m-d"] == null){
     targetString = year + formart["y-m"] + month;
   }

   targetString += " ";

   if(formart["m-a"] != null){
      targetString += morningOrafternoon + " ";
   }
   
   if(formart["h-m"] != null && formart["m-s"] != null){
     targetString +=  hour + formart["h-m"] + minute + formart["m-s"] + second;
   }else if(formart["h-m"] == null && formart["m-s"] != null){
     targetString +=  minute + formart["m-s"] + second;
   }else if(formart["h-m"] != null && formart["m-s"] == null){
     targetString += hour + formart["h-m"] + minute;
   }

   return targetString;

 }

测试：

log(dateAndTimeToString(1594447650000,formart: {"y-m":"/","m-d":"/"}));
log(dateAndTimeToString(1594447650000,formart: {"y-m":"年","m-d":"月"}));
log(dateAndTimeToString(1594447650000,formart: {"y-m":"*","m-d":"*"}));
log(dateAndTimeToString(1594447650000,formart: {"y-m":"-","m-d":"-"}));
log(dateAndTimeToString(1594447650000,formart: {"y-m":"￥","m-d":"￥"}));
log(dateAndTimeToString(1594447650000,formart: {"y-m":"-","m-d":"-","h-m":":"}));
log(dateAndTimeToString(1594447650000,formart: {"y-m":"/","m-d":"/","h-m":":","m-s":":"}));
log(dateAndTimeToString(1594447650000,formart: {"y-m":"/","m-d":"/","m-a":"上、下午","h-m":":","m-s":":"}));
log(dateAndTimeToString(1594447650000,formart: {"m-d":"/","h-m":":"}));
log(dateAndTimeToString(1594447650000,formart: {"m-d":"/","h-m":":","m-s":":"}));

结果：

flutter: 2020/07/11
flutter: 2020年07月11
flutter: 2020*07*11
flutter: 2020-07-11
flutter: 2020￥07￥11
flutter: 2020-07-11 14:07
flutter: 2020/07/11 14:07:30
flutter: 2020/07/11 下午 14:07:30
flutter: 07/11 14:07
flutter: 07/11 14:07:30