TimeZoneInfo.GetSystemTimeZones Metodo

Definizione

Spazio dei nomi:

System

Assembly:

System.Runtime.dll

Overload

GetSystemTimeZones()	Restituisce una raccolta ordinata di tutti i fusi orari per i quali sono disponibili informazioni nel sistema locale.
GetSystemTimeZones(Boolean)	Restituisce un ReadOnlyCollection<T> oggetto contenente tutti gli oggetti TimeZone validi dal computer locale. Questo metodo non genera timeZoneNotFoundException o InvalidTimeZoneException.

GetSystemTimeZones()

Origine:

TimeZoneInfo.cs

Restituisce una raccolta ordinata di tutti i fusi orari per i quali sono disponibili informazioni nel sistema locale.

public:
 static System::Collections::ObjectModel::ReadOnlyCollection<TimeZoneInfo ^> ^ GetSystemTimeZones();

public static System.Collections.ObjectModel.ReadOnlyCollection<TimeZoneInfo> GetSystemTimeZones ();

static member GetSystemTimeZones : unit -> System.Collections.ObjectModel.ReadOnlyCollection<TimeZoneInfo>

Public Shared Function GetSystemTimeZones () As ReadOnlyCollection(Of TimeZoneInfo)

Restituisce

ReadOnlyCollection<TimeZoneInfo>

Raccolta di sola lettura di oggetti TimeZoneInfo.

Eccezioni

OutOfMemoryException

La memoria è insufficiente per archiviare tutte le informazioni sul fuso orario.

SecurityException

L'utente non dispone dell'autorizzazione per leggere le chiavi del Registro di sistema che contengono informazioni sul fuso orario.

Esempio

Nell'esempio seguente viene recuperata una raccolta di oggetti fuso orario che rappresentano i fusi orari definiti in un computer e scrive informazioni su di essi in un file di testo.

using System;
using System.Globalization;
using System.IO;
using System.Collections.ObjectModel;

public class Example
{
   public static void Main()
   {
      const string OUTPUTFILENAME = @"C:\Temp\TimeZoneInfo.txt";
   
      DateTimeFormatInfo dateFormats = CultureInfo.CurrentCulture.DateTimeFormat;
      ReadOnlyCollection<TimeZoneInfo> timeZones = TimeZoneInfo.GetSystemTimeZones(); 
      StreamWriter sw = new StreamWriter(OUTPUTFILENAME, false);
   
      foreach (TimeZoneInfo timeZone in timeZones)
      {
         bool hasDST = timeZone.SupportsDaylightSavingTime;
         TimeSpan offsetFromUtc = timeZone.BaseUtcOffset;
         TimeZoneInfo.AdjustmentRule[] adjustRules;
         string offsetString;
      
         sw.WriteLine("ID: {0}", timeZone.Id);
         sw.WriteLine("   Display Name: {0, 40}", timeZone.DisplayName);
         sw.WriteLine("   Standard Name: {0, 39}", timeZone.StandardName);
         sw.Write("   Daylight Name: {0, 39}", timeZone.DaylightName);
         sw.Write(hasDST ? "   ***Has " : "   ***Does Not Have ");
         sw.WriteLine("Daylight Saving Time***");
         offsetString = String.Format("{0} hours, {1} minutes", offsetFromUtc.Hours, offsetFromUtc.Minutes);
         sw.WriteLine("   Offset from UTC: {0, 40}", offsetString);
         adjustRules = timeZone.GetAdjustmentRules();
         sw.WriteLine("   Number of adjustment rules: {0, 26}", adjustRules.Length);  
         if (adjustRules.Length > 0)
         {
            sw.WriteLine("   Adjustment Rules:");
            foreach (TimeZoneInfo.AdjustmentRule rule in adjustRules)
            {
               TimeZoneInfo.TransitionTime transTimeStart = rule.DaylightTransitionStart;
               TimeZoneInfo.TransitionTime transTimeEnd = rule.DaylightTransitionEnd; 
            
               sw.WriteLine("      From {0} to {1}", rule.DateStart, rule.DateEnd);
               sw.WriteLine("      Delta: {0}", rule.DaylightDelta);
               if (! transTimeStart.IsFixedDateRule)
               {
                  sw.WriteLine("      Begins at {0:t} on {1} of week {2} of {3}", transTimeStart.TimeOfDay, 
                                                                                transTimeStart.DayOfWeek,                                                                                 
                                                                                transTimeStart.Week, 
                                                                                dateFormats.MonthNames[transTimeStart.Month - 1]);
                  sw.WriteLine("      Ends at {0:t} on {1} of week {2} of {3}", transTimeEnd.TimeOfDay,
                                                                                transTimeEnd.DayOfWeek, 
                                                                                transTimeEnd.Week,
                                                                                dateFormats.MonthNames[transTimeEnd.Month - 1]);
               }
               else
               {
                  sw.WriteLine("      Begins at {0:t} on {1} {2}", transTimeStart.TimeOfDay, 
                                                                 transTimeStart.Day, 
                                                                 dateFormats.MonthNames[transTimeStart.Month - 1]);
                  sw.WriteLine("      Ends at {0:t} on {1} {2}", transTimeEnd.TimeOfDay, 
                                                               transTimeEnd.Day, 
                                                               dateFormats.MonthNames[transTimeEnd.Month - 1]);
               }
            }
         }            
      }
      sw.Close();
   }
}

open System
open System.Globalization
open System.IO
open System.Collections.ObjectModel

[<EntryPoint>]
let main _ =
    let OUTPUTFILENAME = @"C:\Temp\TimeZoneInfo.txt"

    let dateFormats = CultureInfo.CurrentCulture.DateTimeFormat
    let timeZones = TimeZoneInfo.GetSystemTimeZones() 
    use sw = new StreamWriter(OUTPUTFILENAME, false)

    for timeZone in timeZones do
        let hasDST = timeZone.SupportsDaylightSavingTime
        let offsetFromUtc = timeZone.BaseUtcOffset
    
        sw.WriteLine $"ID: {timeZone.Id}"
        sw.WriteLine $"   Display Name: {timeZone.DisplayName, 40}"
        sw.WriteLine $"   Standard Name: {timeZone.StandardName, 39}"
        sw.Write $"   Daylight Name: {timeZone.DaylightName, 39}"
        sw.Write(if hasDST then "   ***Has " else "   ***Does Not Have ")
        sw.WriteLine "Daylight Saving Time***"
        let offsetString = $"{offsetFromUtc.Hours} hours, {offsetFromUtc.Minutes} minutes"
        sw.WriteLine $"   Offset from UTC: {offsetString, 40}"
        let adjustRules = timeZone.GetAdjustmentRules()
        sw.WriteLine $"   Number of adjustment rules: {adjustRules.Length, 26}"
        if adjustRules.Length > 0 then
            sw.WriteLine "   Adjustment Rules:"
            for rule in adjustRules do
                let transTimeStart = rule.DaylightTransitionStart
                let transTimeEnd = rule.DaylightTransitionEnd 
            
                sw.WriteLine $"      From {rule.DateStart} to {rule.DateEnd}"
                sw.WriteLine $"      Delta: {rule.DaylightDelta}"
                if not transTimeStart.IsFixedDateRule then
                    sw.WriteLine $"      Begins at {transTimeStart.TimeOfDay:t} on {transTimeStart.DayOfWeek} of week {transTimeStart.Week} of {dateFormats.MonthNames[transTimeStart.Month - 1]}"
                    sw.WriteLine $"      Ends at {transTimeEnd.TimeOfDay:t} on {transTimeEnd.DayOfWeek} of week {transTimeEnd.Week} of {dateFormats.MonthNames[transTimeEnd.Month - 1]}"
                else
                    sw.WriteLine $"      Begins at {transTimeStart.TimeOfDay:t} on {transTimeStart.Day} {dateFormats.MonthNames[transTimeStart.Month - 1]}"
                    sw.WriteLine $"      Ends at {transTimeEnd.TimeOfDay:t} on {transTimeEnd.Day} {dateFormats.MonthNames[transTimeEnd.Month - 1]}"
    0

Imports System.Collections.ObjectModel
Imports System.Globalization
Imports System.IO

Module Example
   Public Sub Main()
      Const OUTPUTFILENAME As String = "C:\Temp\TimeZoneInfo.txt"
      
      Dim timeZones As ReadOnlyCollection(Of TimeZoneInfo) = TimeZoneInfo.GetSystemTimeZones() 
      Dim sw As StreamWriter = New StreamWriter(OUTPUTFILENAME, False)
      
      For Each timeZone As TimeZoneInfo in timeZones
         Dim hasDST As Boolean = timeZone.SupportsDaylightSavingTime
         Dim offsetFromUtc As TimeSpan = timeZone.BaseUtcOffset
         Dim adjustRules() As System.TimeZoneInfo.AdjustmentRule
         Dim offsetString As String
         
         sw.WriteLine("ID: {0}", timeZone.Id)
         sw.WriteLine("   Display Name: {0, 40}", timeZone.DisplayName)
         sw.WriteLine("   Standard Name: {0, 39}", timeZone.StandardName)
         sw.Write("   Daylight Name: {0, 39}", timeZone.DaylightName)
         sw.Write(iif(hasDST, "   ***Has ", "   ***Does Not Have "))
         sw.WriteLine("Daylight Saving Time***")
         offsetString = String.Format("{0} hours, {1} minutes", offsetFromUtc.Hours, offsetFromUtc.Minutes)
         sw.WriteLine("   Offset from UTC: {0, 40}", offsetString)
         adjustRules = timeZone.GetAdjustmentRules()
         sw.WriteLine("   Number of adjustment rules: {0, 26}", adjustRules.Length)  
         If adjustRules.Length > 0 Then
            sw.WriteLine("   Adjustment Rules:")
            For Each rule As TimeZoneInfo.AdjustmentRule In adjustRules
               Dim transTimeStart As TimeZoneInfo.TransitionTime = rule.DaylightTransitionStart
               Dim transTimeEnd As TimeZoneInfo.TransitionTime = rule.DaylightTransitionEnd 
               
               sw.WriteLine("      From {0} to {1}", rule.DateStart, rule.DateEnd)
               sw.WriteLine("      Delta: {0}", rule.DaylightDelta)
               If Not transTimeStart.IsFixedDateRule
                  sw.WriteLine("      Begins at {0:t} on {1} of week {2} of {3}", transTimeStart.TimeOfDay, _
                                                                                transTimeStart.DayOfWeek, _
                                                                                transTimeStart.Week, _
                                                                                MonthName(transTimeStart.Month))
                  sw.WriteLine("      Ends at {0:t} on {1} of week {2} of {3}", transTimeEnd.TimeOfDay, _
                                                                                transTimeEnd.DayOfWeek, _
                                                                                transTimeEnd.Week, _
                                                                                MonthName(transTimeEnd.Month))
               Else
                  sw.WriteLine("      Begins at {0:t} on {1} {2}", transTimeStart.TimeOfDay, _
                                                                 transTimeStart.Day, _
                                                                 MonthName(transTimeStart.Month))
                  sw.WriteLine("      Ends at {0:t} on {1} {2}", transTimeEnd.TimeOfDay, _
                                                               transTimeEnd.Day, _
                                                               MonthName(transTimeEnd.Month))
               End If
            Next
         End If            
      Next
      sw.Close()

#  Get timezone/date details and open a stream writer
$DateFormats    = [System.Globalization.CultureInfo]::CurrentCulture.DateTimeFormat
$TimeZones      = [System.TimeZoneInfo]::GetSystemTimeZones()
$OutputFileName = 'C:\Temp\TimeZoneInfo.txt'
$Sw             = New-Object -TypeName System.IO.StreamWriter -ArgumentList $OutputFileName,$false
# Write overview information
$Sw.WriteLine('{0} Time zones on this system' -f $TimeZones.Count)

# Process each timezone on the system
# Write details to the streamwriter
foreach ($TimeZone in $TimeZones) {
 $HasDST        = $TimeZone.SupportsDaylightSavingTime
 $OffsetFromUtc = $TimeZone.BaseUtcOffset
 $Sw.WriteLine("ID: {0}" -f $TimeZone.Id)
 $Sw.WriteLine("   Display Name:  {0}" -f $TimeZone.DisplayName)
 $Sw.WriteLine("   Standard Name: {0}" -f $TimeZone.StandardName)
 $Sw.Write("   Daylight Name: {0}" -f $TimeZone.DaylightName)
 $Sw.Write( $(If ($HasDST) {"  ***Has: "} Else {"  ***Does Not Have: "}))
 $Sw.WriteLine("Daylight Saving Time***")
 $OffsetString = "{0} hours, {1} minutes" -f $OffsetFromUtc.Hours, $OffsetFromUtc.Minutes
 $Sw.WriteLine("   Offset from UTC: {0}"  -f $offsetString)
 $AdjustRules = $timeZone.GetAdjustmentRules()
 $Sw.WriteLine("   Number of adjustment rules: {0}" -f $adjustRules.Count)
 If ($AdjustRules.Count -gt 0)
 {
    $Sw.WriteLine("   Adjustment Rules:")
    foreach ($Rule in $AdjustRules)
    {
       $TransTimeStart = $Rule.DaylightTransitionStart
       $TransTimeEnd   = $Rule.DaylightTransitionEnd
       $Sw.WriteLine(("     From   {0} to {1}" -f $Rule.DateStart, $Rule.DateEnd))
       $Sw.WriteLine(("       Delta: {0}" -f $Rule.DaylightDelta))
       if (-Not  $TransTimeStart.IsFixedDateRule)
       {
          $Sw.WriteLine(("       Begins at {0:t} on {1} of week {2} of {3}" -f $TransTimeStart.TimeOfDay, 
                                                                             $TransTimeStart.DayOfWeek,                                                                                 
                                                                             $TransTimeStart.Week, 
                                                                             $DateFormats.MonthNames[$TransTimeStart.Month - 1]))
          $Sw.WriteLine(("       Ends at {0:t} on {1} of week {2} of {3}" -f $TransTimeEnd.TimeOfDay,
                                                                             $TransTimeEnd.DayOfWeek, 
                                                                             $TransTimeEnd.Week,
                                                                             $DateFormats.MonthNames[[int] $TransTimeEnd.Month - 1]))
       }
     else
       {
         $Sw.WriteLine(("       Begins at {0:t} on {1} {2}" -f $TransTimeStart.TimeOfDay, 
                                                             $TransTimeStart.Day, 
                                                             $DateFormats.MonthNames[$transTimeStart.Month - 1]))
         $Sw.WriteLine(("       Ends at {0:t} on {1} {2}"   -f $TransTimeEnd.TimeOfDay, 
                                                             $TransTimeEnd.Day, 
                                                             $DateFormats.MonthNames[$transTimeEnd.Month - 1]))        
       }
    } # End of processing each adjustment rule
 } # End of checking adjustment rules
} # End of processing Time Zones

# Close stream writer then display output in notepad
$Sw.Close() 

#  Output of 1st three time zones:
#  135 Time zones on this system
#  ID: Dateline Standard Time
#     Display Name:  (UTC-12:00) International Date Line West
#     Standard Name: Dateline Standard Time
#     Daylight Name: Dateline Summer Time  ***Does Not Have: Daylight Saving Time***
#     Offset from UTC: -12 hours, 0 minutes
#     Number of adjustment rules: 0
#  ID: UTC-11
#     Display Name:  (UTC-11:00) Co-ordinated Universal Time-11
#     Standard Name: UTC-11
#     Daylight Name: UTC-11  ***Does Not Have: Daylight Saving Time***
#     Offset from UTC: -11 hours, 0 minutes
#     Number of adjustment rules: 0
#  ID: Aleutian Standard Time
#     Display Name:  (UTC-10:00) Aleutian Islands
#     Standard Name: Aleutian Standard Time
#     Daylight Name: Aleutian Summer Time  ***Has: Daylight Saving Time***
#     Offset from UTC: -10 hours, 0 minutes
#     Number of adjustment rules: 2
#     Adjustment Rules:
#       From   01/01/0001 00:00:00 to 31/12/2006 00:00:00
#         Delta: 01:00:00
#         Begins at 02:00 on Sunday of week 1 of April
#         Ends at 02:00 on Sunday of week 5 of October
#       From   01/01/2007 00:00:00 to 31/12/9999 00:00:00
#         Delta: 01:00:00
#         Begins at 02:00 on Sunday of week 2 of March
#         Ends at 02:00 on Sunday of week 1 of November

Commenti

Il GetSystemTimeZones metodo recupera tutte le informazioni sul fuso orario disponibili dalle sottochiavi della chiave HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Time Zones del Registro di sistema nei sistemi Windows e dalla libreria ICU in Linux e macOS. Se non è possibile recuperare e analizzare correttamente i valori per specifiche proprietà stringa di singoli TimeZoneInfo oggetti, questo metodo imposta il valore su una stringa vuota ("").

Importante

Il GetSystemTimeZones metodo restituisce una raccolta di TimeZoneInfo oggetti solo per i fusi orari definiti nel Registro di sistema di Windows o nella libreria di ICU. Non include i fusi orari creati usando gli overload del CreateCustomTimeZone metodo . Sono accessibili solo tramite il riferimento all'oggetto restituito dal metodo di creazione del fuso orario.

La raccolta restituita da questo metodo viene ordinata in base all'offset UTC e, per i fusi orari con lo stesso offset UTC, in base al nome visualizzato utilizzando le impostazioni cultura correnti. Per informazioni sul nome visualizzato, vedere DisplayName.

L'oggetto ReadOnlyCollection<T> restituito da questo metodo supporta l'interfaccia IEnumerable<T> , il che significa che può essere eseguito l'iterazione usando le foreach istruzioni (in C#) o For Each…Next (in Visual Basic). Ogni iterazione del ciclo fornisce l'oggetto successivo TimeZoneInfo nell'insieme.

La raccolta di TimeZoneInfo oggetti rappresenta i fusi orari definiti nel computer locale. Non fornisce necessariamente informazioni complete per tutti i fusi orari durante tutti i periodi di tempo. Se l'applicazione richiede fusi orari non trovati nel computer locale, è possibile creare fusi orari personalizzati usando gli overload del CreateCustomTimeZone metodo . Per altre informazioni, vedere Procedura: Creare fusi orari senza regole di regolazione e Procedura: Creare fusi orari con regole di regolazione.

È anche possibile determinare se un singolo fuso orario è definito nel computer locale chiamando il FindSystemTimeZoneById metodo e specificando l'identificatore del fuso orario che si desidera recuperare come parametro.

GetSystemTimeZones(Boolean)

Origine:

TimeZoneInfo.cs

Restituisce un ReadOnlyCollection<T> oggetto contenente tutti gli oggetti TimeZone validi dal computer locale. Questo metodo non genera timeZoneNotFoundException o InvalidTimeZoneException.

public:
 static System::Collections::ObjectModel::ReadOnlyCollection<TimeZoneInfo ^> ^ GetSystemTimeZones(bool skipSorting);

public static System.Collections.ObjectModel.ReadOnlyCollection<TimeZoneInfo> GetSystemTimeZones (bool skipSorting);

static member GetSystemTimeZones : bool -> System.Collections.ObjectModel.ReadOnlyCollection<TimeZoneInfo>

Public Shared Function GetSystemTimeZones (skipSorting As Boolean) As ReadOnlyCollection(Of TimeZoneInfo)

Parametri

skipSorting

Boolean

Se true, la raccolta restituita potrebbe non essere necessariamente ordinata.

Restituisce

ReadOnlyCollection<TimeZoneInfo>

Commenti

Impostando il parametro skipSorting su true, il metodo tenterà di evitare di ordinare la raccolta restituita. Questa opzione può essere utile quando il chiamante non richiede un elenco ordinato e mira a migliorare le prestazioni.