TimeZoneInfo.GetSystemTimeZones Metodo

Definizione

Restituisce una raccolta ordinata di tutti i fusi orari per i quali sono disponibili informazioni nel sistema locale.Returns a sorted collection of all the time zones about which information is available on the local system.

public:
 static System::Collections::ObjectModel::ReadOnlyCollection<TimeZoneInfo ^> ^ GetSystemTimeZones();
public static System.Collections.ObjectModel.ReadOnlyCollection<TimeZoneInfo> GetSystemTimeZones ();
[System.Security.SecurityCritical]
[System.Security.SecurityTreatAsSafe]
public static System.Collections.ObjectModel.ReadOnlyCollection<TimeZoneInfo> GetSystemTimeZones ();
static member GetSystemTimeZones : unit -> System.Collections.ObjectModel.ReadOnlyCollection<TimeZoneInfo>
[<System.Security.SecurityCritical>]
[<System.Security.SecurityTreatAsSafe>]
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.A read-only collection of TimeZoneInfo objects.

Attributi

Eccezioni

La memoria è insufficiente per archiviare tutte le informazioni sul fuso orario.There is insufficient memory to store all time zone information.

L'utente non dispone dell'autorizzazione per leggere le chiavi del Registro di sistema che contengono informazioni sul fuso orario.The user does not have permission to read from the registry keys that contain time zone information.

Esempio

Nell'esempio seguente viene recuperata una raccolta di oggetti fusi orari che rappresentano i fusi orari definiti in un computer e che scrive le relative informazioni in un file di testo.The following example retrieves a collection of time zone objects that represent the time zones defined on a computer and writes information about them to a text file.

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();
   }
}
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 disponibili sul fuso orario 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.The GetSystemTimeZones method retrieves all available time zone information from the subkeys of the registry's HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Time Zones key on Windows systems and from the ICU Library on Linux and macOS. Se non è in grado di recuperare e analizzare i valori per determinate proprietà di stringa di singoli TimeZoneInfo oggetti, questo metodo imposta il relativo valore su una stringa vuota ("").If it is unable to successfully retrieve and parse values for particular string properties of individual TimeZoneInfo objects, this method sets their value to an empty string ("").

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.The GetSystemTimeZones method returns a collection of TimeZoneInfo objects only for time zones defined in the Windows registry or the ICU library. Non include i fusi orari creati usando gli overload del CreateCustomTimeZone metodo.It does not include time zones created using the overloads of the CreateCustomTimeZone method. Sono accessibili solo tramite il riferimento all'oggetto restituito dal metodo di creazione del fuso orario.These are accessible only through the object reference returned by the time zone creation method.

La raccolta restituita da questo metodo è ordinata in base all'offset UTC e, per i fusi orari con lo stesso offset UTC, dal nome visualizzato utilizzando le impostazioni cultura correnti.The collection returned by this method is sorted by UTC offset and, for time zones that have the same UTC offset, by the display name using the current culture. Per informazioni sul nome visualizzato, vedere DisplayName .For information about the display name, see DisplayName.

L' ReadOnlyCollection<T> oggetto restituito da questo metodo supporta l' IEnumerable<T> interfaccia, il che significa che è possibile iterare usando le foreach istruzioni (in C#) o For Each…Next (in Visual Basic).The ReadOnlyCollection<T> object returned by this method supports the IEnumerable<T> interface, which means that it can be iterated using the foreach (in C#) or For Each…Next (in Visual Basic) statements. Ogni iterazione del ciclo fornisce l' TimeZoneInfo oggetto successivo nella raccolta.Each iteration of the loop provides the next TimeZoneInfo object in the collection.

La raccolta di TimeZoneInfo oggetti rappresenta i fusi orari definiti nel computer locale e non fornisce necessariamente informazioni complete per tutti i fusi orari durante tutti i periodi di tempo.The collection of TimeZoneInfo objects represents time zones defined on the local computer; it does not necessarily provide complete information for all time zones during all time periods. Se l'applicazione richiede fusi orari non trovati nel computer locale, è possibile creare fusi orari personalizzati usando gli overload del CreateCustomTimeZone metodo.If your application requires time zones not found on the local computer, you can create custom time zones using the overloads of the CreateCustomTimeZone method. Per altre informazioni, vedere procedura: creare fusi orari senza regole di rettifica e procedura: creare fusi orari con regole di rettifica.For more information, see How to: Create Time Zones Without Adjustment Rules and How to: Create Time Zones with Adjustment Rules.

È inoltre possibile determinare se nel computer locale viene definito un singolo fuso orario chiamando il FindSystemTimeZoneById metodo e fornendo l'identificatore del fuso orario che si desidera recuperare come parametro.You can also determine whether an individual time zone is defined on the local computer by calling the FindSystemTimeZoneById method and providing the identifier of the time zone you want to retrieve as a parameter.

Si applica a