VB.NET DateTime.ToLocalTime方法代碼示例

Module Example
    Sub Main()
      Dim localDateTime, univDateTime As DateTime
      
      Console.WriteLine("Enter a date and time.")
      Dim strDateTime As String = Console.ReadLine()
      Try
         localDateTime = DateTime.Parse(strDateTime)
         univDateTime = localDateTime.ToUniversalTime()
         Console.WriteLine("{0} local time is {1} universal time.", 
                           localDateTime, univDateTime)
      Catch exp As FormatException
         Console.WriteLine("Invalid format.")
      End Try

      Console.WriteLine("Enter a date and time in universal time.")
      strDateTime = Console.ReadLine()
      Try
         univDateTime = DateTime.Parse(strDateTime)
         localDateTime = univDateTime.ToLocalTime()
  
         Console.WriteLine("{0} universal time is {1} local time.", _
                           univDateTime, localDateTime)
      Catch exp As FormatException
         Console.WriteLine("Invalid format.")
      End Try
    End Sub
End Module
' The example displays output like the following when run on a 
' computer whose culture is en-US in the Pacific Standard Time zone:
'     Enter a date and time.
'     12/10/2015 6:18 AM
'     12/10/2015 6:18:00 AM local time is 12/10/2015 2:18:00 PM universal time.
'     Enter a date and time in universal time.
'     12/20/2015 6:42:00
'     12/20/2015 6:42:00 AM universal time is 12/19/2015 10:42:00 PM local time.

' This code example demonstrates the DateTime Kind, Now, and
' UtcNow properties, and the SpecifyKind(), ToLocalTime(), 
' and ToUniversalTime() methods.
Class Sample
    Public Shared Sub Main() 
        ' Get the date and time for the current moment, adjusted 
        ' to the local time zone.
        Dim saveNow As DateTime = DateTime.Now
        
        ' Get the date and time for the current moment expressed 
        ' as coordinated universal time (UTC).
        Dim saveUtcNow As DateTime = DateTime.UtcNow
        Dim myDt As DateTime
        
        ' Display the value and Kind property of the current moment 
        ' expressed as UTC and local time.
        DisplayNow("UtcNow: ..........", saveUtcNow)
        DisplayNow("Now: .............", saveNow)
        Console.WriteLine()
        
        ' Change the Kind property of the current moment to 
        ' DateTimeKind.Utc and display the result.
        myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Utc)
        Display("Utc: .............", myDt)
        
        ' Change the Kind property of the current moment to 
        ' DateTimeKind.Local and display the result.
        myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Local)
        Display("Local: ...........", myDt)
        
        ' Change the Kind property of the current moment to 
        ' DateTimeKind.Unspecified and display the result.
        myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Unspecified)
        Display("Unspecified: .....", myDt)
    End Sub
    
    ' Display the value and Kind property of a DateTime structure, the 
    ' DateTime structure converted to local time, and the DateTime 
    ' structure converted to universal time. 

    Public Shared datePatt As String = "M/d/yyyy hh:mm:ss tt"
    
    Public Shared Sub Display(ByVal title As String, ByVal inputDt As DateTime) 
        Dim dispDt As DateTime = inputDt
        Dim dtString As String
        
        ' Display the original DateTime.
        dtString = dispDt.ToString(datePatt)
        Console.WriteLine("{0} {1}, Kind = {2}", title, dtString, dispDt.Kind)
        
        ' Convert inputDt to local time and display the result. 
        ' If inputDt.Kind is DateTimeKind.Utc, the conversion is performed.
        ' If inputDt.Kind is DateTimeKind.Local, the conversion is not performed.
        ' If inputDt.Kind is DateTimeKind.Unspecified, the conversion is 
        ' performed as if inputDt was universal time.
        dispDt = inputDt.ToLocalTime()
        dtString = dispDt.ToString(datePatt)
        Console.WriteLine("  ToLocalTime:     {0}, Kind = {1}", dtString, dispDt.Kind)
        
        ' Convert inputDt to universal time and display the result. 
        ' If inputDt.Kind is DateTimeKind.Utc, the conversion is not performed.
        ' If inputDt.Kind is DateTimeKind.Local, the conversion is performed.
        ' If inputDt.Kind is DateTimeKind.Unspecified, the conversion is 
        ' performed as if inputDt was local time.
        dispDt = inputDt.ToUniversalTime()
        dtString = dispDt.ToString(datePatt)
        Console.WriteLine("  ToUniversalTime: {0}, Kind = {1}", dtString, dispDt.Kind)
        Console.WriteLine()
    End Sub
    
    
    ' Display the value and Kind property for DateTime.Now and DateTime.UtcNow.

    Public Shared Sub DisplayNow(ByVal title As String, ByVal inputDt As DateTime) 
        Dim dtString As String = inputDt.ToString(datePatt)
        Console.WriteLine("{0} {1}, Kind = {2}", title, dtString, inputDt.Kind)
    End Sub
End Class

Module Example
   Public Sub Main()
      Dim date1 As New Date(2010, 3, 14, 2, 30, 0, DateTimeKind.Local)
      Console.WriteLine("Invalid time: {0}", _
                        TimeZoneInfo.Local.IsInvalidTime(date1))
      Dim utcDate1 As Date = date1.ToUniversalTime()
      Dim date2 As Date = utcDate1.ToLocalTime()
      Console.WriteLine("{0} --> {1}", date1, date2)      
   End Sub
End Module