TimeZoneInfo.FromSerializedString(String) Method

Definition

Namespace:

System

Assembly:

System.Runtime.dll

Source:

TimeZoneInfo.cs

Deserializes a string to re-create an original serialized TimeZoneInfo object.

public:
 static TimeZoneInfo ^ FromSerializedString(System::String ^ source);

public static TimeZoneInfo FromSerializedString (string source);

static member FromSerializedString : string -> TimeZoneInfo

Public Shared Function FromSerializedString (source As String) As TimeZoneInfo

Parameters

source

String

The string representation of the serialized TimeZoneInfo object.

Returns

TimeZoneInfo

The original serialized object.

Exceptions

ArgumentException

The source parameter is Empty.

ArgumentNullException

The source parameter is a null string.

SerializationException

The source parameter cannot be deserialized back into a TimeZoneInfo object.

Examples

The following example tries to retrieve the Antarctica/South Pole time zone from the local system. If it fails, the code tries to retrieve information about the time zone from a text file in the application directory. If this attempt fails, the code creates the time zone and writes information about the time zone to the text file.

private TimeZoneInfo InitializeTimeZone()
{
   TimeZoneInfo southPole = null;
   // Determine if South Pole time zone is defined in system
   try
   {
      southPole = TimeZoneInfo.FindSystemTimeZoneById("Antarctica/South Pole Standard Time");
   }
   // Time zone does not exist; create it, store it in a text file, and return it
   catch
   {
      const string filename = @".\TimeZoneInfo.txt";
      bool found = false;
      
      if (File.Exists(filename))
      {
         StreamReader reader = new StreamReader(filename);
         string timeZoneInfo;
         while (reader.Peek() >= 0)
         {
            timeZoneInfo = reader.ReadLine();
            if (timeZoneInfo.Contains("Antarctica/South Pole"))
            {
               southPole = TimeZoneInfo.FromSerializedString(timeZoneInfo);
               reader.Close();
               found = true;
               break;
            }   
         }
      }
      if (! found)
      {               
         // Define transition times to/from DST
         TimeZoneInfo.TransitionTime startTransition = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(new DateTime(1, 1, 1, 2, 0, 0), 10, 1, DayOfWeek.Sunday); 
         TimeZoneInfo.TransitionTime endTransition = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(new DateTime(1, 1, 1, 2, 0, 0), 3, 3, DayOfWeek.Sunday);
         // Define adjustment rule
         TimeSpan delta = new TimeSpan(1, 0, 0);
         TimeZoneInfo.AdjustmentRule adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(new DateTime(1989, 10, 1), DateTime.MaxValue.Date, delta, startTransition, endTransition);
         // Create array for adjustment rules
         TimeZoneInfo.AdjustmentRule[] adjustments = {adjustment};
         // Define other custom time zone arguments
         string displayName = "(GMT+12:00) Antarctica/South Pole";
         string standardName = "Antarctica/South Pole Standard Time";
         string daylightName = "Antarctica/South Pole Daylight Time";
         TimeSpan offset = new TimeSpan(12, 0, 0);
         southPole = TimeZoneInfo.CreateCustomTimeZone(standardName, offset, displayName, standardName, daylightName, adjustments);
         // Write time zone to the file
         StreamWriter writer = new StreamWriter(filename, true);
         writer.WriteLine(southPole.ToSerializedString());
         writer.Close();
      }
   }
   return southPole;
}

let initializeTimeZone () =
    // Determine if South Pole time zone is defined in system
    try
        TimeZoneInfo.FindSystemTimeZoneById "Antarctica/South Pole Standard Time"
    // Time zone does not exist create it, store it in a text file, and return it
    with _ ->
        let filename = @".\TimeZoneInfo.txt"
        let mutable southPole = Unchecked.defaultof<TimeZoneInfo>
        let mutable found = false
        
        if File.Exists filename then
            use reader = new StreamReader(filename)
            while reader.Peek() >= 0 && not found do
                let timeZoneInfo = reader.ReadLine()
                if timeZoneInfo.Contains "Antarctica/South Pole" then
                    southPole <- TimeZoneInfo.FromSerializedString timeZoneInfo
                    reader.Close()
                    found <- true
        if not found then
            // Define transition times to/from DST
            let startTransition = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(DateTime(1, 1, 1, 2, 0, 0), 10, 1, DayOfWeek.Sunday) 
            let endTransition = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(DateTime(1, 1, 1, 2, 0, 0), 3, 3, DayOfWeek.Sunday)
            // Define adjustment rule
            let delta = TimeSpan(1, 0, 0)
            let adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(DateTime(1989, 10, 1), DateTime.MaxValue.Date, delta, startTransition, endTransition)
            // Create array for adjustment rules
            let adjustments = [| adjustment |]
            // Define other custom time zone arguments
            let displayName = "(GMT+12:00) Antarctica/South Pole"
            let standardName = "Antarctica/South Pole Standard Time"
            let daylightName = "Antarctica/South Pole Daylight Time"
            let offset = TimeSpan(12, 0, 0)
            southPole <- TimeZoneInfo.CreateCustomTimeZone(standardName, offset, displayName, standardName, daylightName, adjustments)
            // Write time zone to the file
            use writer = new StreamWriter(filename, true)
            writer.WriteLine(southPole.ToSerializedString())
        southPole

Private Function InitializeTimeZone() As TimeZoneInfo
   Dim southPole As TimeZoneInfo = Nothing
   ' Determine if South Pole time zone is defined in system
   Try
      southPole = TimeZoneInfo.FindSystemTimeZoneById("Antarctica/South Pole Standard Time")
   ' Time zone does not exist; create it, store it in a text file, and return it
   Catch e As TimeZoneNotFoundException
      Dim found As Boolean
      Const filename As String = ".\TimeZoneInfo.txt"
      
      If File.Exists(filename) Then
         Dim reader As StreamReader = New StreamReader(fileName)
         Dim timeZoneString As String
         Do While reader.Peek() >= 0
            timeZoneString = reader.ReadLine()
            If timeZoneString.Contains("Antarctica/South Pole") Then
               southPole = TimeZoneInfo.FromSerializedString(timeZoneString)
               reader.Close()
               found = True
               Exit Do
            End If   
         Loop
      End If
      If Not found Then               
         ' Define transition times to/from DST
         Dim startTransition As TimeZoneInfo.TransitionTime = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(#02:00:00#, 10, 1, DayOfWeek.Sunday) 
         Dim endTransition As TimeZoneInfo.TransitionTime = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(#02:00:00#, 3, 3, DayOfWeek.Sunday)
         ' Define adjustment rule
         Dim delta As TimeSpan = New TimeSpan(1, 0, 0)
         Dim adjustment As TimeZoneInfo.AdjustmentRule = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(#10/01/1989#, Date.MaxValue.Date, delta, startTransition, endTransition)
         ' Create array for adjustment rules
         Dim adjustments() As TimeZoneInfo.AdjustmentRule = {adjustment}
         ' Define other custom time zone arguments
         Dim displayName As String = "(GMT+12:00) Antarctica/South Pole"
         Dim standardName As String = "Antarctica/South Pole Standard Time"
         Dim daylightName As String = "Antarctica/South Pole Daylight Time"
         Dim offset As TimeSpan = New TimeSpan(12, 0, 0)
         southPole = TimeZoneInfo.CreateCustomTimeZone(standardName, offset, displayName, standardName, daylightName, adjustments)
         ' Write time zone to the file
         Dim writer As StreamWriter = New StreamWriter(filename, True)
         writer.WriteLine(southPole.ToSerializedString())
         writer.Close()
      End If
   End Try
   Return southPole
End Function

Remarks

There is an alternative to providing all the code required to create a time zone that is not found in the registry on Windows or in the ICU Library on Linux and macOS. You can define a custom time zone and either use the ToSerializedString method in a standalone executable or use an application's setup program to save the time zone as a string. The application can then retrieve this string from its storage location and instantiate it using the FromSerializedString method.

See also

• ToSerializedString()
• How to: Restore Time Zones from an Embedded Resource