得到总秒数

var i = TimeSpan.FromTicks(startDate.Ticks).TotalSeconds;

并从秒获取datetime

var thatDateTime = new DateTime().AddSeconds(i)

private string ConvertTime(double miliSeconds)
{
    var timeSpan = TimeSpan.FromMilliseconds(totalMiliSeconds);
    // Converts the total miliseconds to the human readable time format
    return timeSpan.ToString(@"hh\:mm\:ss\:fff");
}

/ /测试

    [TestCase(1002, "00:00:01:002")]
    [TestCase(700011, "00:11:40:011")]
    [TestCase(113879834, "07:37:59:834")]
    public void ConvertTime_ResturnsCorrectString(double totalMiliSeconds, string expectedMessage)
    {
        // Arrange
        var obj = new Class();;

        // Act
        var resultMessage = obj.ConvertTime(totalMiliSeconds);

        // Assert
        Assert.AreEqual(expectedMessage, resultMessage);
    }

 TimeSpan t = TimeSpan.FromSeconds(EnergyRestoreTimer.Instance.SecondsForRestore);
            string sTime = EnergyRestoreTimer.Instance.SecondsForRestore < 3600
                ? $"{t.Hours:D2}:{t.Minutes:D2}:{t.Seconds:D2}"
                : $"{t.Minutes:D2}:{t.Seconds:D2}";
            time.text = sTime;

对于。net > 4.0你可以使用

TimeSpan time = TimeSpan.FromSeconds(seconds);

//here backslash is must to tell that colon is
//not the part of format, it just a character that we want in output
string str = time .ToString(@"hh\:mm\:ss\:fff");

如果你想要日期时间格式，你也可以这样做

TimeSpan time = TimeSpan.FromSeconds(seconds);
DateTime dateTime = DateTime.Today.Add(time);
string displayTime = dateTime.ToString("hh:mm:tt");

有关更多信息，您可以检查自定义TimeSpan格式字符串

得到总秒数

var i = TimeSpan.FromTicks(startDate.Ticks).TotalSeconds;

并从秒获取datetime

var thatDateTime = new DateTime().AddSeconds(i)

如果您知道您有一个秒数，您可以通过调用TimeSpan来创建一个TimeSpan值。FromSeconds:

 TimeSpan ts = TimeSpan.FromSeconds(80);

您可以获取天、小时、分钟或秒的数量。或者使用一个ToString重载以任何您喜欢的方式输出它。