C＃使用类似'dd MMMM yyyy HH:mm'的字符串来定义日期和时间应显示的格式。
momentjs 中的等价物是'DD MMMM YYYY HH:mm'。
是否有某些功能可以将一种格式定义转换为另一种格式定义而不管格式说明符源格式包含哪些（合法）组合？
基本上我想要的是：
function toMomentJsFormatDefinition(cSharpFormatDefinition) {
// should convert all format strings described here https://msdn.microsoft.com/en-us/library/8kb3ddd4%28v=vs.110%29.aspx
}
console.log(toMomentJsFormatDefinition('dd MMMM yyyy HH:mm'));
// outputs DD MMMM YYYY HH:mm
理想情况下，toMomentJsFormatDefinition应该在一些已经编写且经过良好测试的库中定义，我将在我的项目中使用。
答案 0 :(得分：9)
我有相同的任务，并创建了以下实用程序函数，将DateTime格式字符串从Dotnet转换为MomentJS格式。
用法：
string lDotNetFormat = "yyyy-MM-dd HH:mm";
string lMomentJSFormat = MomentJSHelpers.GenerateMomentJSFormatString(lDotNetFormat, fTolerant: true, fCulture: CultureInfo.InvariantCulture);
MessageBox.Show(lMomentJSFormat);
// Output: YYYY[-]MM[-]DD[ ]HH[:]mm
代码：
using System;
using System.Globalization;
using System.Text;
namespace XYZ
{
/// <summary>
/// Class with helper functions to work with MomentJS
/// </summary>
public static class MomentJSHelpers
{
/// <summary>
/// Exception that is throws when trying to convert a dotnet datetime format string
/// to a MomentJS format string and this fails because we have an element in the format string
/// that has no equivalent in MomentJS
/// </summary>
public class UnsupportedFormatException : Exception
{
public UnsupportedFormatException (string fMessage): base(fMessage)
{
}
}
/// <summary>
/// Translate a dotnet datetime format string to a MomentJS format string<br/>
// Restriction:<br/>
// Fractional Seconds Lowecase F and Uppercase F are difficult to translate to MomentJS, so closest
// translation used
/// </summary>
/// <param name="fText">The dotnet datetime format string to convert</param>
/// <param name="fTolerant">If true, some cases where there is not exact equivalent in MomentJs is
/// handled by generating a similar format instead of throwing a UnsupportedFormatException exception.</param>
/// <param name="fCulture">The Culture to use. If none, the current Culture is used</param>
/// <returns>A format string to be used in MomentJS</returns>
/// <exception cref="UnsupportedFormatException">Conversion fails because we have an element in the format string
/// that has no equivalent in MomentJS</exception>
/// <exception cref="FormatException">fText is no valid DateTime format string in dotnet</exception>
/// <exception cref="ArgumentNullException">fText is null</exception>
public static string GenerateMomentJSFormatString(string fText, bool fTolerant = true, CultureInfo fCulture = null)
{
fCulture = fCulture ?? CultureInfo.CurrentCulture;
string lResult;
if(fText == null)
{
throw new ArgumentNullException("fText");
}
if(fText.Length == 0)
{
lResult = "";
}
if (fText.Length == 1)
{
lResult = GenerateMomentJSFormatStringFromStandardFormat(fText, fTolerant, fCulture);
}
else
{
lResult = GenerateMomentJSFormatStringFromUserFormat(fText, fTolerant, fCulture);
}
return lResult;
}
/// <summary>
/// State of StateMachine while scanning Format DateTime string
/// </summary>
private enum State
{
None,
LowerD1,
LowerD2,
LowerD3,
LowerD4,
LowerF1,
LowerF2,
LowerF3,
LowerF4,
LowerF5,
LowerF6,
LowerF7,
CapitalF1,
CapitalF2,
CapitalF3,
CapitalF4,
CapitalF5,
CapitalF6,
CapitalF7,
LowerG,
LowerH1,
LowerH2,
CapitalH1,
CapitalH2,
CapitalK,
LowerM1,
LowerM2,
CapitalM1,
CapitalM2,
CapitalM3,
CapitalM4,
LowerS1,
LowerS2,
LowerT1,
LowerT2,
LowerY1,
LowerY2,
LowerY3,
LowerY4,
LowerY5,
LowerZ1,
LowerZ2,
LowerZ3,
InSingleQuoteLiteral,
InDoubleQuoteLiteral,
EscapeSequence
}
private static string GenerateMomentJSFormatStringFromUserFormat(string fText, bool fTolerant, CultureInfo fCulture)
{
StringBuilder lResult = new StringBuilder();
State lState = State.None;
StringBuilder lTokenBuffer = new StringBuilder();
var ChangeState = new Action<State>((State fNewState) =>
{
switch (lState)
{
case State.LowerD1:
lResult.Append("D");
break;
case State.LowerD2:
lResult.Append("DD");
break;
case State.LowerD3:
lResult.Append("ddd");
break;
case State.LowerD4:
lResult.Append("dddd");
break;
case State.LowerF1:
case State.CapitalF1:
lResult.Append("S");
break;
case State.LowerF2:
case State.CapitalF2:
lResult.Append("SS");
break;
case State.LowerF3:
case State.CapitalF3:
lResult.Append("SSS");
break;
case State.LowerF4:
case State.CapitalF4:
lResult.Append("SSSS");
break;
case State.LowerF5:
case State.CapitalF5:
lResult.Append("SSSSS");
break;
case State.LowerF6:
case State.CapitalF6:
lResult.Append("SSSSSS");
break;
case State.LowerF7:
case State.CapitalF7:
lResult.Append("SSSSSSS");
break;
case State.LowerG:
throw new UnsupportedFormatException("Era not supported in MomentJS");
case State.LowerH1:
lResult.Append("h");
break;
case State.LowerH2:
lResult.Append("hh");
break;
case State.CapitalH1:
lResult.Append("H");
break;
case State.CapitalH2:
lResult.Append("HH");
break;
case State.LowerM1:
lResult.Append("m");
break;
case State.LowerM2:
lResult.Append("mm");
break;
case State.CapitalM1:
lResult.Append("M");
break;
case State.CapitalM2:
lResult.Append("MM");
break;
case State.CapitalM3:
lResult.Append("MMM");
break;
case State.CapitalM4:
lResult.Append("MMMM");
break;
case State.LowerS1:
lResult.Append("s");
break;
case State.LowerS2:
lResult.Append("ss");
break;
case State.LowerT1:
if (fTolerant)
{
lResult.Append("A");
}
else
{
throw new UnsupportedFormatException("Single Letter AM/PM not supported in MomentJS");
}
break;
case State.LowerT2:
lResult.Append("A");
break;
case State.LowerY1:
if (fTolerant)
{
lResult.Append("YY");
}
else
{
throw new UnsupportedFormatException("Single Letter Year not supported in MomentJS");
}
break;
case State.LowerY2:
lResult.Append("YY");
break;
case State.LowerY3:
if (fTolerant)
{
lResult.Append("YYYY");
}
else
{
throw new UnsupportedFormatException("Three Letter Year not supported in MomentJS");
}
break;
case State.LowerY4:
lResult.Append("YYYY");
break;
case State.LowerY5:
if(fTolerant)
{
lResult.Append("Y");
}
else
{
throw new UnsupportedFormatException("Five or more Letter Year not supported in MomentJS");
}
break;
case State.LowerZ1:
case State.LowerZ2:
if (fTolerant)
{
lResult.Append("ZZ");
}
else
{
throw new UnsupportedFormatException("Hours offset not supported in MomentJS");
}
break;
case State.LowerZ3:
lResult.Append("Z");
break;
case State.InSingleQuoteLiteral:
case State.InDoubleQuoteLiteral:
case State.EscapeSequence:
foreach (var lCharacter in lTokenBuffer.ToString())
{
lResult.Append("[" + lCharacter + "]");
}
break;
}
lTokenBuffer.Clear();
lState = fNewState;
}); // End ChangeState
foreach (var character in fText)
{
if (lState == State.EscapeSequence)
{
lTokenBuffer.Append(character);
ChangeState(State.None);
}
else if (lState == State.InDoubleQuoteLiteral)
{
if (character == '\"')
{
ChangeState(State.None);
}
else
{
lTokenBuffer.Append(character);
}
}
else if (lState == State.InSingleQuoteLiteral)
{
if (character == '\'')
{
ChangeState(State.None);
}
else
{
lTokenBuffer.Append(character);
}
}
else
{
switch (character)
{
case 'd':
switch (lState)
{
case State.LowerD1:
lState = State.LowerD2;
break;
case State.LowerD2:
lState = State.LowerD3;
break;
case State.LowerD3:
lState = State.LowerD4;
break;
case State.LowerD4:
break;
default:
ChangeState(State.LowerD1);
break;
}
break;
case 'f':
switch (lState)
{
case State.LowerF1:
lState = State.LowerF2;
break;
case State.LowerF2:
lState = State.LowerF3;
break;
case State.LowerF3:
lState = State.LowerF4;
break;
case State.LowerF4:
lState = State.LowerF5;
break;
case State.LowerF5:
lState = State.LowerF6;
break;
case State.LowerF6:
lState = State.LowerF7;
break;
case State.LowerF7:
break;
default:
ChangeState(State.LowerF1);
break;
}
break;
case 'F':
switch (lState)
{
case State.CapitalF1:
lState = State.CapitalF2;
break;
case State.CapitalF2:
lState = State.CapitalF3;
break;
case State.CapitalF3:
lState = State.CapitalF4;
break;
case State.CapitalF4:
lState = State.CapitalF5;
break;
case State.CapitalF5:
lState = State.CapitalF6;
break;
case State.CapitalF6:
lState = State.CapitalF7;
break;
case State.CapitalF7:
break;
default:
ChangeState(State.CapitalF1);
break;
}
break;
case 'g':
switch (lState)
{
case State.LowerG:
break;
default:
ChangeState(State.LowerG);
break;
}
break;
case 'h':
switch (lState)
{
case State.LowerH1:
lState = State.LowerH2;
break;
case State.LowerH2:
break;
default:
ChangeState(State.LowerH1);
break;
}
break;
case 'H':
switch (lState)
{
case State.CapitalH1:
lState = State.CapitalH2;
break;
case State.CapitalH2:
break;
default:
ChangeState(State.CapitalH1);
break;
}
break;
case 'K':
ChangeState(State.None);
if (fTolerant)
{
lResult.Append("Z");
}
else
{
throw new UnsupportedFormatException("TimeZoneInformation not supported in MomentJS");
}
break;
case 'm':
switch (lState)
{
case State.LowerM1:
lState = State.LowerM2;
break;
case State.LowerM2:
break;
default:
ChangeState(State.LowerM1);
break;
}
break;
case 'M':
switch (lState)
{
case State.CapitalM1:
lState = State.CapitalM2;
break;
case State.CapitalM2:
lState = State.CapitalM3;
break;
case State.CapitalM3:
lState = State.CapitalM4;
break;
case State.CapitalM4:
break;
default:
ChangeState(State.CapitalM1);
break;
}
break;
case 's':
switch (lState)
{
case State.LowerS1:
lState = State.LowerS2;
break;
case State.LowerS2:
break;
default:
ChangeState(State.LowerS1);
break;
}
break;
case 't':
switch (lState)
{
case State.LowerT1:
lState = State.LowerT2;
break;
case State.LowerT2:
break;
default:
ChangeState(State.LowerT1);
break;
}
break;
case 'y':
switch (lState)
{
case State.LowerY1:
lState = State.LowerY2;
break;
case State.LowerY2:
lState = State.LowerY3;
break;
case State.LowerY3:
lState = State.LowerY4;
break;
case State.LowerY4:
lState = State.LowerY5;
break;
case State.LowerY5:
break;
default:
ChangeState(State.LowerY1);
break;
}
break;
case 'z':
switch (lState)
{
case State.LowerZ1:
lState = State.LowerZ2;
break;
case State.LowerZ2:
lState = State.LowerZ3;
break;
case State.LowerZ3:
break;
default:
ChangeState(State.LowerZ1);
break;
}
break;
case ':':
ChangeState(State.None);
lResult.Append("[" + fCulture.DateTimeFormat.TimeSeparator + "]");
break;
case '/':
ChangeState(State.None);
lResult.Append("[" + fCulture.DateTimeFormat.DateSeparator + "]");
break;
case '\"':
ChangeState(State.InDoubleQuoteLiteral);
break;
case '\'':
ChangeState(State.InSingleQuoteLiteral);
break;
case '%':
ChangeState(State.None);
break;
case '\\':
ChangeState(State.EscapeSequence);
break;
default:
ChangeState(State.None);
lResult.Append("[" + character + "]");
break;
}
}
}
if (lState == State.EscapeSequence || lState == State.InDoubleQuoteLiteral || lState == State.InSingleQuoteLiteral)
{
throw new FormatException("Invalid Format String");
}
ChangeState(State.None);
return lResult.ToString();
}
private static string GenerateMomentJSFormatStringFromStandardFormat(string fText, bool fTolerant, CultureInfo fCulture)
{
string result;
switch (fText)
{
case "d":
result = GenerateMomentJSFormatStringFromUserFormat(fCulture.DateTimeFormat.ShortDatePattern, fTolerant, fCulture);
break;
case "D":
result = GenerateMomentJSFormatStringFromUserFormat(fCulture.DateTimeFormat.LongDatePattern, fTolerant, fCulture);
break;
case "f":
result = GenerateMomentJSFormatStringFromUserFormat(fCulture.DateTimeFormat.LongDatePattern + " " + fCulture.DateTimeFormat.ShortTimePattern, fTolerant, fCulture);
break;
case "F":
result = GenerateMomentJSFormatStringFromUserFormat(fCulture.DateTimeFormat.FullDateTimePattern, fTolerant, fCulture);
break;
case "g":
result = GenerateMomentJSFormatStringFromUserFormat(fCulture.DateTimeFormat.ShortDatePattern + " " + fCulture.DateTimeFormat.ShortTimePattern, fTolerant, fCulture);
break;
case "G":
result = GenerateMomentJSFormatStringFromUserFormat(fCulture.DateTimeFormat.ShortDatePattern + " " + fCulture.DateTimeFormat.LongTimePattern, fTolerant, fCulture);
break;
case "M":
case "m":
result = GenerateMomentJSFormatStringFromUserFormat(fCulture.DateTimeFormat.MonthDayPattern, fTolerant, fCulture);
break;
case "O":
case "o":
result = GenerateMomentJSFormatStringFromUserFormat("yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fffffffK", fTolerant, fCulture);
break;
case "R":
case "r":
throw new UnsupportedFormatException("RFC 1123 not supported in MomentJS");
case "s":
result = GenerateMomentJSFormatStringFromUserFormat(fCulture.DateTimeFormat.SortableDateTimePattern, fTolerant, fCulture);
break;
case "t":
result = GenerateMomentJSFormatStringFromUserFormat(fCulture.DateTimeFormat.ShortTimePattern, fTolerant, fCulture);
break;
case "T":
result = GenerateMomentJSFormatStringFromUserFormat(fCulture.DateTimeFormat.LongTimePattern, fTolerant, fCulture);
break;
case "u":
throw new UnsupportedFormatException("Universal Sortable Format not supported in MomentJS");
case "U":
throw new UnsupportedFormatException("Universal Fulll Format not supported in MomentJS");
case "Y":
case "y":
result = GenerateMomentJSFormatStringFromUserFormat(fCulture.DateTimeFormat.YearMonthPattern, fTolerant, fCulture);
break;
default:
throw new FormatException("Unknown Standard DateTime Format");
}
return result;
}
}
}