TimeZoneInfo.GetAdjustmentRules メソッド

定義

現在の TimeZoneInfo オブジェクトに適用する TimeZoneInfo.AdjustmentRule オブジェクトの配列を取得します。Retrieves an array of TimeZoneInfo.AdjustmentRule objects that apply to the current TimeZoneInfo object.

public:
 cli::array <TimeZoneInfo::AdjustmentRule ^> ^ GetAdjustmentRules();
public TimeZoneInfo.AdjustmentRule[] GetAdjustmentRules ();
member this.GetAdjustmentRules : unit -> TimeZoneInfo.AdjustmentRule[]
Public Function GetAdjustmentRules () As TimeZoneInfo.AdjustmentRule()

戻り値

AdjustmentRule[]

このタイム ゾーンのオブジェクトの配列。An array of objects for this time zone.

例外

システムには、調整規則のメモリ内コピーを作成するのに十分なメモリがありません。The system does not have enough memory to make an in-memory copy of the adjustment rules.

次の例では、ローカルシステムで定義されているすべてのタイムゾーンを取得し、その調整規則に関する完全な情報をコンソールに表示します。The following example retrieves all time zones that are defined on the local system and displays complete information about their adjustment rules to the console.

private enum WeekOfMonth 
{
   First = 1,
   Second = 2,
   Third = 3,
   Fourth = 4,
   Last = 5,
}

private static void ShowStartAndEndDates()
{
   // Get all time zones from system
   ReadOnlyCollection<TimeZoneInfo> timeZones = TimeZoneInfo.GetSystemTimeZones();
   string[] monthNames = CultureInfo.CurrentCulture.DateTimeFormat.MonthNames;
   // Get each time zone
   foreach (TimeZoneInfo timeZone in timeZones)
   {
      TimeZoneInfo.AdjustmentRule[] adjustments = timeZone.GetAdjustmentRules();
      // Display message for time zones with no adjustments
      if (adjustments.Length == 0)
      {
         Console.WriteLine("{0} has no adjustment rules", timeZone.StandardName);
      }   
      else
      {
         // Handle time zones with 1 or 2+ adjustments differently
         bool showCount = false;
         int ctr = 0;
         string spacer = "";
         
         Console.WriteLine("{0} Adjustment rules", timeZone.StandardName);
         if (adjustments.Length > 1)
         {
            showCount = true;
            spacer = "   ";
         }   
         // Iterate adjustment rules
         foreach (TimeZoneInfo.AdjustmentRule adjustment in adjustments)
         {
            if (showCount)
            { 
               Console.WriteLine("   Adjustment rule #{0}", ctr+1);
               ctr++;
            }
            // Display general adjustment information
            Console.WriteLine("{0}   Start Date: {1:D}", spacer, adjustment.DateStart);
            Console.WriteLine("{0}   End Date: {1:D}", spacer, adjustment.DateEnd);
            Console.WriteLine("{0}   Time Change: {1}:{2:00} hours", spacer, 
                              adjustment.DaylightDelta.Hours, adjustment.DaylightDelta.Minutes);
            // Get transition start information
            TimeZoneInfo.TransitionTime transitionStart = adjustment.DaylightTransitionStart;
            Console.Write("{0}   Annual Start: ", spacer);
            if (transitionStart.IsFixedDateRule)
            {
               Console.WriteLine("On {0} {1} at {2:t}", 
                                 monthNames[transitionStart.Month - 1], 
                                 transitionStart.Day, 
                                 transitionStart.TimeOfDay);
            }
            else
            {
               Console.WriteLine("The {0} {1} of {2} at {3:t}", 
                                 ((WeekOfMonth)transitionStart.Week).ToString(), 
                                 transitionStart.DayOfWeek.ToString(), 
                                 monthNames[transitionStart.Month - 1], 
                                 transitionStart.TimeOfDay);
            }
            // Get transition end information
            TimeZoneInfo.TransitionTime transitionEnd = adjustment.DaylightTransitionEnd;
            Console.Write("{0}   Annual End: ", spacer);
            if (transitionEnd.IsFixedDateRule)
            {
               Console.WriteLine("On {0} {1} at {2:t}", 
                                 monthNames[transitionEnd.Month - 1], 
                                 transitionEnd.Day, 
                                 transitionEnd.TimeOfDay);
            }
            else
            {
               Console.WriteLine("The {0} {1} of {2} at {3:t}", 
                                 ((WeekOfMonth)transitionEnd.Week).ToString(), 
                                 transitionEnd.DayOfWeek.ToString(), 
                                 monthNames[transitionEnd.Month - 1], 
                                 transitionEnd.TimeOfDay);
            }
         }
      }   
      Console.WriteLine();
   } 
}
Private Enum WeekOfMonth As Integer
   First = 1
   Second = 2
   Third = 3
   Fourth = 4
   Last = 5
End Enum

Private Sub ShowStartAndEndDates()
   ' Get all time zones from system
   Dim timeZones As ReadOnlyCollection(Of TimeZoneInfo) = TimeZoneInfo.GetSystemTimeZones()
   ' Get each time zone
   For Each timeZone As TimeZoneInfo In timeZones
      Dim adjustments() As TimeZoneInfo.AdjustmentRule = timeZone.GetAdjustmentRules()
      ' Display message for time zones with no adjustments
      If adjustments.Length = 0 Then
         Console.WriteLine("{0} has no adjustment rules", timeZone.StandardName)
      Else
         ' Handle time zones with 1 or 2+ adjustments differently
         Dim showCount As Boolean = False
         Dim ctr As Integer = 0
         Dim spacer As String = ""
         
         Console.WriteLine("{0} Adjustment rules", timeZone.StandardName)
         If adjustments.Length > 1 Then showCount = True : spacer = "   "  
         ' Iterate adjustment rules
         For Each adjustment As TimeZoneInfo.AdjustmentRule in adjustments
            If showCount Then 
               Console.WriteLine("   Adjustment rule #{0}", ctr+1)
               ctr += 1
            End If
            ' Display general adjustment information
            Console.WriteLine("{0}   Start Date: {1:D}", spacer, adjustment.DateStart)
            Console.WriteLine("{0}   End Date: {1:D}", spacer, adjustment.DateEnd)
            Console.WriteLine("{0}   Time Change: {1}:{2:00} hours", spacer, _
                              adjustment.DaylightDelta.Hours, adjustment.DaylightDelta.Minutes)
            ' Get transition start information
            Dim transitionStart As TimeZoneInfo.TransitionTime = adjustment.DaylightTransitionStart
            Console.Write("{0}   Annual Start: ", spacer)
            If transitionStart.IsFixedDateRule Then
               Console.WriteLine("On {0} {1} at {2:t}", _
                                 MonthName(transitionStart.Month), _
                                 transitionStart.Day, _
                                 transitionStart.TimeOfDay)
            Else
               Console.WriteLine("The {0} {1} of {2} at {3:t}", _
                                 CType(transitionStart.Week, WeekOfMonth).ToString(), _
                                 transitionStart.DayOfWeek.ToString(), _
                                 MonthName(transitionStart.Month), _
                                 transitionStart.TimeOfDay)
            End If
            ' Get transition end information
            Dim transitionEnd As TimeZoneInfo.TransitionTime = adjustment.DaylightTransitionEnd
                              
            Console.Write("{0}   Annual End: ", spacer)
            If transitionEnd.IsFixedDateRule Then
               Console.WriteLine("On {0} {1} at {2:t}", _
                                 MonthName(transitionEnd.Month), _
                                 transitionEnd.Day, _
                                 transitionEnd.TimeOfDay)
            Else
               Console.WriteLine("The {0} {1} of {2} at {3:t}", _
                                 CType(transitionEnd.Week, WeekOfMonth).ToString(), _
                                 transitionEnd.DayOfWeek.ToString(), _
                                 MonthName(transitionEnd.Month), _
                                 transitionEnd.TimeOfDay)
            End If
         Next
      End If   
      Console.WriteLine()
   Next 
End Sub

注釈

メソッドは、 GetAdjustmentRules オブジェクトの配列を取得し System.TimeZoneInfo.AdjustmentRule ます。The GetAdjustmentRules method retrieves an array of System.TimeZoneInfo.AdjustmentRule objects. 配列内の各オブジェクトは、そのタイムゾーン調整の有効な開始日と終了日、およびデルタ (調整によって時間が変化する正確な量) を定義します。Each object in the array defines the effective start and end date of that time zone adjustment, as well as its delta (the exact amount by which the adjustment causes the time to change). さらに、2つのプロパティは、 System.TimeZoneInfo.TransitionTime 標準時間との間の毎年の遷移が発生するタイミングを定義するオブジェクトを返します。In addition, two properties return System.TimeZoneInfo.TransitionTime objects that define when each annual transition to and from standard time occurs.

タイムゾーンに複数の調整規則が含まれている場合、通常は、最初の (インデックス0の) から最後 (インデックス 1) までの順序で並べ替えられ Length ます。If a time zone has multiple adjustment rules, they are generally ordered from earliest (at index 0) to latest (at index Length - 1).

タイムゾーンに調整規則がない場合、 GetAdjustmentRules メソッドは空の配列 ( Length がゼロを持つ配列) を返します。If a time zone has no adjustment rules, the GetAdjustmentRules method returns an empty array (an array whose Length is zero).

メソッドによって返される配列の要素に対する変更 GetAdjustmentRules は、特定のタイムゾーンに属する調整規則には反映されません。Any modifications to the elements of the array returned by the GetAdjustmentRules method are not reflected in the adjustment rules that belong to a particular time zone. タイムゾーンの調整規則 (夏時間前後の履歴を反映するなど) を変更するには、既存のタイムゾーンを変更するのではなく、適切な調整規則を指定して新しいタイムゾーンを作成する必要があります。To modify a time zone's adjustment rules (such as to reflect its historical transition to and from daylight saving time) you must create a new time zone with the appropriate adjustment rules, rather than modify the existing one.

適用対象

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