将日期和时间格式字符串从 moment.js 转换为 C# 格式

Question

是否有任何现有的函数/库可以将日期和时间格式从 转换moment.js为C#？

我将从中接收日期和时间格式（只有格式，没有日期和时间值）moment.js并且需要在C#.

例如：

YYYY-MM-DD h:mm A
//this is the format received from moment.js

然后，如果我有一个DateTimein C#，我需要将它显示为

2018-06-14 2:30 PM
//this is equivalent with YYYY-MM-dd h:mm tt

我需要这样的东西：

string ConvertToCustomDateTimeFormat(string momentJsFormat){
   // should convert all moment.js date and time format to https://docs.microsoft.com/en-us/dotnet/standard/base-types/custom-date-and-time-format-strings
}

然后我可以这样使用它：

string dateTimeFormat = ConvertToCustomDateTimeFormat("YYYY-MM-DD h:mm A");
//dateTimeFormat value should be YYYY-MM-dd h:mm tt
string formattedDateTime = myDateTime.ToString(dateTimeFormat);
Console.WriteLine(formattedDateTime);
// output will be 2018-06-14 2:30 PM

Answer 1

我发现转换日期和时间格式的函数从C#到moment.js在这里。所以，我创建了一个函数来做相反的事情（从moment.js到C#）。我把它贴在这里以防有人也需要它。

/// <summary>
/// Class to help convert moment.js date and time format to C# format
/// </summary>
public static class MomentJSConverter
{
    private enum State
    {
        None,
        LowerA,
        CapitalA,
        LowerD1,
        LowerD2,
        LowerD3,
        LowerD4,
        CapitalD1,
        CapitalD2,
        LowerH1,
        LowerH2,
        CapitalH1,
        CapitalH2,
        LowerM1,
        LowerM2,
        CapitalM1,
        CapitalM2,
        CapitalM3,
        CapitalM4,
        LowerS1,
        LowerS2,
        CapitalS1,
        CapitalS2,
        CapitalS3,
        CapitalS4,
        CapitalS5,
        CapitalS6,
        CapitalS7,
        CapitalY1,
        CapitalY2,
        CapitalY3,
        CapitalY4,
        CapitalZ
    }

    public static string GenerateCSharpFormatString(string momentJsFormat)
    {
        StringBuilder resultBuilder = new StringBuilder();
        State resultState = State.None;
        StringBuilder tokenBuffer = new StringBuilder();

        var ChangeState = new Action<State>((State fNewState) =>
        {
            switch (resultState)
            {
                case State.LowerA:
                case State.CapitalA:
                    resultBuilder.Append("tt");
                    break;
                case State.LowerD3:
                    resultBuilder.Append("ddd");
                    break;
                case State.LowerD4:
                    resultBuilder.Append("dddd");
                    break;
                case State.CapitalD1:
                    resultBuilder.Append("d");
                    break;
                case State.CapitalD2:
                    resultBuilder.Append("dd");
                    break;
                case State.LowerH1:
                    resultBuilder.Append("h");
                    break;
                case State.LowerH2:
                    resultBuilder.Append("hh");
                    break;
                case State.CapitalH1:
                    resultBuilder.Append("H");
                    break;
                case State.CapitalH2:
                    resultBuilder.Append("HH");
                    break;
                case State.LowerM1:
                    resultBuilder.Append("m");
                    break;
                case State.LowerM2:
                    resultBuilder.Append("mm");
                    break;
                case State.CapitalM1:
                    resultBuilder.Append("M");
                    break;
                case State.CapitalM2:
                    resultBuilder.Append("MM");
                    break;
                case State.CapitalM3:
                    resultBuilder.Append("MMM");
                    break;
                case State.CapitalM4:
                    resultBuilder.Append("MMMM");
                    break;
                case State.LowerS1:
                    resultBuilder.Append("s");
                    break;
                case State.LowerS2:
                    resultBuilder.Append("ss");
                    break;
                case State.CapitalS1:
                    resultBuilder.Append("f");
                    break;
                case State.CapitalS2:
                    resultBuilder.Append("ff");
                    break;
                case State.CapitalS3:
                    resultBuilder.Append("fff");
                    break;
                case State.CapitalS4:
                    resultBuilder.Append("ffff");
                    break;
                case State.CapitalS5:
                    resultBuilder.Append("fffff");
                    break;
                case State.CapitalS6:
                    resultBuilder.Append("ffffff");
                    break;
                case State.CapitalS7:
                    resultBuilder.Append("fffffff");
                    break;
                case State.CapitalY2:
                    resultBuilder.Append("yy");
                    break;
                case State.CapitalY4:
                    resultBuilder.Append("yyyy");
                    break;
                case State.CapitalZ:
                    resultBuilder.Append("zzz");
                    break;
            }

            tokenBuffer.Clear();
            resultState = fNewState;
        });

        foreach (var character in momentJsFormat)
        {
            switch (character)
            {
                case 'a':
                    switch (resultState)
                    {
                        case State.LowerA:
                            break;
                        default:
                            ChangeState(State.LowerA);
                            break;
                    }
                    break;
                case 'A':
                    switch (resultState)
                    {
                        case State.CapitalA:
                            break;
                        default:
                            ChangeState(State.CapitalA);
                            break;
                    }
                    break;
                case 'd':
                    switch (resultState)
                    {
                        case State.LowerD1:
                            resultState = State.LowerD2;
                            break;
                        case State.LowerD2:
                            resultState = State.LowerD3;
                            break;
                        case State.LowerD3:
                            resultState = State.LowerD4;
                            break;
                        case State.LowerD4:
                            break;
                        default:
                            ChangeState(State.LowerD1);
                            break;
                    }
                    break;
                case 'D':
                    switch (resultState)
                    {
                        case State.CapitalD1:
                            resultState = State.CapitalD2;
                            break;
                        case State.CapitalD2:
                            break;
                        default:
                            ChangeState(State.CapitalD1);
                            break;
                    }
                    break;
                case 'h':
                    switch (resultState)
                    {
                        case State.LowerH1:
                            resultState = State.LowerH2;
                            break;
                        case State.LowerH2:
                            break;
                        default:
                            ChangeState(State.LowerH1);
                            break;
                    }
                    break;
                case 'H':
                    switch (resultState)
                    {
                        case State.CapitalH1:
                            resultState = State.CapitalH2;
                            break;
                        case State.CapitalH2:
                            break;
                        default:
                            ChangeState(State.CapitalH1);
                            break;
                    }
                    break;
                case 'm':
                    switch (resultState)
                    {
                        case State.LowerM1:
                            resultState = State.LowerM2;
                            break;
                        case State.LowerM2:
                            break;
                        default:
                            ChangeState(State.LowerM1);
                            break;
                    }
                    break;
                case 'M':
                    switch (resultState)
                    {
                        case State.CapitalM1:
                            resultState = State.CapitalM2;
                            break;
                        case State.CapitalM2:
                            resultState = State.CapitalM3;
                            break;
                        case State.CapitalM3:
                            resultState = State.CapitalM4;
                            break;
                        case State.CapitalM4:
                            break;
                        default:
                            ChangeState(State.CapitalM1);
                            break;
                    }
                    break;
                case 's':
                    switch (resultState)
                    {
                        case State.LowerS1:
                            resultState = State.LowerS2;
                            break;
                        case State.LowerS2:
                            break;
                        default:
                            ChangeState(State.LowerS1);
                            break;
                    }
                    break;
                case 'S':
                    switch (resultState)
                    {
                        case State.CapitalS1:
                            resultState = State.CapitalS2;
                            break;
                        case State.CapitalS2:
                            resultState = State.CapitalS3;
                            break;
                        case State.CapitalS3:
                            resultState = State.CapitalS4;
                            break;
                        case State.CapitalS4:
                            resultState = State.CapitalS5;
                            break;
                        case State.CapitalS5:
                            resultState = State.CapitalS6;
                            break;
                        case State.CapitalS6:
                            resultState = State.CapitalS7;
                            break;
                        case State.CapitalS7:
                            break;
                        default:
                            ChangeState(State.CapitalS1);
                            break;
                    }
                    break;
                case 'Y':
                    switch (resultState)
                    {
                        case State.CapitalY1:
                            resultState = State.CapitalY2;
                            break;
                        case State.CapitalY2:
                            resultState = State.CapitalY3;
                            break;
                        case State.CapitalY3:
                            resultState = State.CapitalY4;
                            break;
                        case State.CapitalY4:
                            break;
                        default:
                            ChangeState(State.CapitalY1);
                            break;
                    }
                    break;
                case 'Z':
                    switch (resultState)
                    {
                        case State.CapitalZ:
                            break;
                        default:
                            ChangeState(State.CapitalZ);
                            break;
                    }
                    break;
                default:
                    ChangeState(State.None);
                    resultBuilder.Append(character);
                    break;
            }
        }

        ChangeState(State.None);
        return resultBuilder.ToString();
    }
}