关于DateTime.ToString()格式化

用于备忘录：

主要内容来自MSDN：

C#内置了对于时间格式化的本地化。

下面的代码中不仅有关于输入模式的设置，还包含了时间的区域性设置。

DateTime.Now.ToString("关键字")代码为官方提供：

下方有个人截图：图像的最前括号中的字母，即是格式化的关键字。

using System;
using System.Globalization;
using System.Threading;

public class Sample
{
public static void M()
{

string msgShortDate = "(d) Short date: . . . . . . . ";
string msgLongDate = "(D) Long date:. . . . . . . . ";
string msgShortTime = "(t) Short time: . . . . . . . ";
string msgLongTime = "(T) Long time:. . . . . . . . ";
string msgFullDateShortTime =
"(f) Full date/short time: . . ";
string msgFullDateLongTime =
"(F) Full date/long time:. . . ";
string msgGeneralDateShortTime =
"(g) General date/short time:. ";
string msgGeneralDateLongTime =
"(G) General date/long time (default):\n" +
" . . . . . . . . . . . . . ";
string msgMonth = "(M) Month:. . . . . . . . . . ";
string msgRFC1123 = "(R) RFC1123:. . . . . . . . . ";
string msgSortable = "(s) Sortable: . . . . . . . . ";
string msgUniSortInvariant =
"(u) Universal sortable (invariant):\n" +
" . . . . . . . . . . . . . ";
string msgUniFull = "(U) Universal full date/time: ";
string msgYear = "(Y) Year: . . . . . . . . . . ";
string msgRoundtripLocal = "(o) Roundtrip (local):. . . . ";
string msgRoundtripUTC = "(o) Roundtrip (UTC):. . . . . ";
string msgRoundtripUnspecified = "(o) Roundtrip (Unspecified):. ";

string msg1 = "Use ToString(String) and the current thread culture.\n";
string msg2 = "Use ToString(String, IFormatProvider) and a specified culture.\n";
string msgCulture = "Culture:";
string msgThisDate = "This date and time: {0}\n";

DateTime thisDate = DateTime.Now;
DateTime utcDate = thisDate.ToUniversalTime();
DateTime unspecifiedDate = new DateTime(2000, 3, 20, 13, 2, 3, 0, DateTimeKind.Unspecified);
CultureInfo ci;

// Format the current date and time in various ways.
Console.Clear();
Console.WriteLine("Standard DateTime Format Specifiers:\n");
Console.WriteLine(msgThisDate, thisDate);
Console.WriteLine(msg1);

// Display the thread current culture, which is used to format the values.
ci = Thread.CurrentThread.CurrentCulture;
Console.WriteLine("{0,-30}{1}\n", msgCulture, ci.DisplayName);

Console.WriteLine(msgShortDate + thisDate.ToString("d"));
Console.WriteLine(msgLongDate + thisDate.ToString("D"));
Console.WriteLine(msgShortTime + thisDate.ToString("t"));
Console.WriteLine(msgLongTime + thisDate.ToString("T"));
Console.WriteLine(msgFullDateShortTime + thisDate.ToString("f"));
Console.WriteLine(msgFullDateLongTime + thisDate.ToString("F"));
Console.WriteLine(msgGeneralDateShortTime + thisDate.ToString("g"));
Console.WriteLine(msgGeneralDateLongTime + thisDate.ToString("G"));
Console.WriteLine(msgMonth + thisDate.ToString("M"));
Console.WriteLine(msgRFC1123 + utcDate.ToString("R"));
Console.WriteLine(msgSortable + thisDate.ToString("s"));
Console.WriteLine(msgUniSortInvariant + utcDate.ToString("u"));
Console.WriteLine(msgUniFull + thisDate.ToString("U"));
Console.WriteLine(msgYear + thisDate.ToString("Y"));
Console.WriteLine(msgRoundtripLocal + thisDate.ToString("o"));
Console.WriteLine(msgRoundtripUTC + utcDate.ToString("o"));
Console.WriteLine(msgRoundtripUnspecified + unspecifiedDate.ToString("o"));

Console.WriteLine();

// Display the same values using a CultureInfo object. The CultureInfo class
// implements IFormatProvider.
Console.WriteLine(msg2);

// Display the culture used to format the values.
ci = new CultureInfo("de-DE");
Console.WriteLine("{0,-30}{1}\n", msgCulture, ci.DisplayName);

Console.WriteLine(msgShortDate + thisDate.ToString("d", ci));
Console.WriteLine(msgLongDate + thisDate.ToString("D", ci));
Console.WriteLine(msgShortTime + thisDate.ToString("t", ci));
Console.WriteLine(msgLongTime + thisDate.ToString("T", ci));
Console.WriteLine(msgFullDateShortTime + thisDate.ToString("f", ci));
Console.WriteLine(msgFullDateLongTime + thisDate.ToString("F", ci));
Console.WriteLine(msgGeneralDateShortTime + thisDate.ToString("g", ci));
Console.WriteLine(msgGeneralDateLongTime + thisDate.ToString("G", ci));
Console.WriteLine(msgMonth + thisDate.ToString("M", ci));
Console.WriteLine(msgRFC1123 + utcDate.ToString("R", ci));
Console.WriteLine(msgSortable + thisDate.ToString("s", ci));
Console.WriteLine(msgUniSortInvariant + utcDate.ToString("u", ci));
Console.WriteLine(msgUniFull + thisDate.ToString("U", ci));
Console.WriteLine(msgYear + thisDate.ToString("Y", ci));
Console.WriteLine(msgRoundtripLocal + thisDate.ToString("o", ci));
Console.WriteLine(msgRoundtripUTC + utcDate.ToString("o", ci));
Console.WriteLine(msgRoundtripUnspecified + unspecifiedDate.ToString("o", ci));

Console.WriteLine();
}
}