C# DateTimeOffset.TryParseExact方法代码示例

TextReader conIn = Console.In;
 TextWriter conOut = Console.Out;
 int tries = 0;
 string input = String.Empty;

 string[] formats = new string[] {"M/dd/yyyy HH:m zzz", "MM/dd/yyyy HH:m zzz", 
                                  "M/d/yyyy HH:m zzz", "MM/d/yyyy HH:m zzz", 
                                  "M/dd/yy HH:m zzz", "MM/dd/yy HH:m zzz", 
                                  "M/d/yy HH:m zzz", "MM/d/yy HH:m zzz",                                 
                                  "M/dd/yyyy H:m zzz", "MM/dd/yyyy H:m zzz", 
                                  "M/d/yyyy H:m zzz", "MM/d/yyyy H:m zzz", 
                                  "M/dd/yy H:m zzz", "MM/dd/yy H:m zzz", 
                                  "M/d/yy H:m zzz", "MM/d/yy H:m zzz",                               
                                  "M/dd/yyyy HH:mm zzz", "MM/dd/yyyy HH:mm zzz", 
                                  "M/d/yyyy HH:mm zzz", "MM/d/yyyy HH:mm zzz", 
                                  "M/dd/yy HH:mm zzz", "MM/dd/yy HH:mm zzz", 
                                  "M/d/yy HH:mm zzz", "MM/d/yy HH:mm zzz",                                 
                                  "M/dd/yyyy H:mm zzz", "MM/dd/yyyy H:mm zzz", 
                                  "M/d/yyyy H:mm zzz", "MM/d/yyyy H:mm zzz", 
                                  "M/dd/yy H:mm zzz", "MM/dd/yy H:mm zzz", 
                                  "M/d/yy H:mm zzz", "MM/d/yy H:mm zzz"};   
 IFormatProvider provider = CultureInfo.InvariantCulture.DateTimeFormat;
 DateTimeOffset result;

 do {
    conOut.WriteLine("Enter a date, time, and offset (MM/DD/YYYY HH:MM +/-HH:MM),");
    conOut.Write("Then press Enter: ");
    input = conIn.ReadLine();
    conOut.WriteLine(); 
    if (DateTimeOffset.TryParseExact(input, formats, provider, 
                                    DateTimeStyles.AllowWhiteSpaces, 
                                    out result))
    {                                          
       break;
    }
    else
    {  
       Console.WriteLine("Unable to parse {0}.", input);      
       tries++;
    }
 } while (tries < 3);
 if (tries >= 3)
    Console.WriteLine("Exiting application without parsing {0}", input);
 else
    Console.WriteLine("{0} was converted to {1}", input, result.ToString());                                                     
 // Some successful sample interactions with the user might appear as follows:
 //    Enter a date, time, and offset (MM/DD/YYYY HH:MM +/-HH:MM),
 //    Then press Enter: 12/08/2007 6:54 -6:00
 //    
 //    12/08/2007 6:54 -6:00 was converted to 12/8/2007 6:54:00 AM -06:00         
 //    
 //    Enter a date, time, and offset (MM/DD/YYYY HH:MM +/-HH:MM),
 //    Then press Enter: 12/8/2007 06:54 -06:00
 //    
 //    12/8/2007 06:54 -06:00 was converted to 12/8/2007 6:54:00 AM -06:00
 //    
 //    Enter a date, time, and offset (MM/DD/YYYY HH:MM +/-HH:MM),
 //    Then press Enter: 12/5/07 6:54 -6:00
 //    
 //    12/5/07 6:54 -6:00 was converted to 12/5/2007 6:54:00 AM -06:00

string dateString, format;  
DateTimeOffset result;
IFormatProvider provider = CultureInfo.InvariantCulture;

// Parse date-only value with invariant culture and assume time is UTC.
dateString = "06/15/2008";
format = "d";
if (DateTimeOffset.TryParseExact(dateString, format, provider, 
                                 DateTimeStyles.AssumeUniversal, 
                                 out result))
   Console.WriteLine("'{0}' converts to {1}.", dateString, result.ToString());
else
   Console.WriteLine("'{0}' is not in the correct format.", dateString);

// Parse date-only value with leading white space.
// Should return False because only trailing white space is  
// specified in method call.
dateString = " 06/15/2008";
if (DateTimeOffset.TryParseExact(dateString, format, provider, 
                                 DateTimeStyles.AllowTrailingWhite, 
                                 out result))
   Console.WriteLine("'{0}' converts to {1}.", dateString, result.ToString());
else
   Console.WriteLine("'{0}' is not in the correct format.", dateString);

// Parse date and time value, and allow all white space.
dateString = " 06/15/   2008  15:15    -05:00";
format = "MM/dd/yyyy H:mm zzz";
if (DateTimeOffset.TryParseExact(dateString, format, provider, 
                                 DateTimeStyles.AllowWhiteSpaces, 
                                 out result))
   Console.WriteLine("'{0}' converts to {1}.", dateString, result.ToString());
else
   Console.WriteLine("'{0}' is not in the correct format.", dateString);

// Parse date and time and convert to UTC.
dateString = "  06/15/2008 15:15:30 -05:00";   
format = "MM/dd/yyyy H:mm:ss zzz";       
if (DateTimeOffset.TryParseExact(dateString, format, provider, 
                                DateTimeStyles.AllowWhiteSpaces | 
                                DateTimeStyles.AdjustToUniversal, 
                                out result))
   Console.WriteLine("'{0}' converts to {1}.", dateString, result.ToString());
else
   Console.WriteLine("'{0}' is not in the correct format.", dateString);

//引入命名空间
using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      string[] dateStrings = { "2018-08-18T12:45:16.0000000Z",
                               "2018/08/18T12:45:16.0000000Z",
                               "2018-18-08T12:45:16.0000000Z",
                               "2018-08-18T12:45:16.0000000",                               
                               " 2018-08-18T12:45:16.0000000Z ",
                               "2018-08-18T12:45:16.0000000+02:00",
                               "2018-08-18T12:45:16.0000000-07:00" }; 
      
      ParseWithISO8601(dateStrings, DateTimeStyles.None);
      Console.WriteLine("\n-----\n");
      ParseWithISO8601(dateStrings, DateTimeStyles.AllowWhiteSpaces);
      Console.WriteLine("\n-----\n");
      ParseWithISO8601(dateStrings, DateTimeStyles.AdjustToUniversal);
      Console.WriteLine("\n-----\n");
      ParseWithISO8601(dateStrings, DateTimeStyles.AssumeLocal);
      Console.WriteLine("\n-----\n");
      ParseWithISO8601(dateStrings, DateTimeStyles.AssumeUniversal);   }

   private static void ParseWithISO8601(string[] dateStrings, DateTimeStyles styles)
   {   
      Console.WriteLine($"Parsing with {styles}:");
      DateTimeOffset date;
      foreach (var dateString in dateStrings)
      {
         if (DateTimeOffset.TryParseExact(dateString, "O", null, styles, out date))
         {
            Console.WriteLine($"   {dateString,-35} --> {date:yyyy-MM-dd HH:mm:ss.FF zzz}");
         }
         else
         {
            Console.WriteLine($"   Unable to convert '{dateString}'");
         }   
      } 
   }
}