VB.Net/Development/Date Operation

Материал из VB Эксперт
Версия от 15:45, 26 мая 2010; Admin (обсуждение | вклад) (1 версия)
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Add a day, a month and a year to a Date

<source lang="vbnet"> Imports System Public Class MainClass

   Shared Sub Main()
       Dim dteStartDate As Date
       Dim dteChangedDate As Date
       "Start off in 2400
       dteStartDate = #2/28/2400#
       "Add a day and display the results
       dteChangedDate = dteStartDate.AddDays(1)
       System.Console.WriteLine(dteChangedDate.ToLongDateString)
       "Add some months and display the results
       dteChangedDate = dteStartDate.AddMonths(6)
       System.Console.WriteLine(dteChangedDate.ToLongDateString)
       "Subtract a year and display the results
       dteChangedDate = dteStartDate.AddYears(-1)
       System.Console.WriteLine(dteChangedDate.ToLongDateString)
   End Sub

End Class

      </source>


Add time (days, hours) to current time

<source lang="vbnet"> Imports System.IO Module Module1

   Sub Main()
       Dim Dt As DateTime = Now()
       Dim NewDT As DateTime = Now()
       Console.WriteLine("Current date and time: " & Dt)
       NewDT = NewDT.AddHours(5)
       Console.WriteLine("Five hours from now is: " & NewDT)
   End Sub

End Module


      </source>


Date Time and TimeSpan Demo

<source lang="vbnet"> Imports System Imports System.Diagnostics Public Class MainClass

   Shared Sub Main()
       Const TRIALS As Integer = 10000000
       Dim start_time As DateTime
       Dim stop_time As DateTime
       Dim elapsed_time As TimeSpan
       Dim i As Integer
       start_time = Now
       For i = 1 To TRIALS
       Next i
       stop_time = Now
       elapsed_time = stop_time.Subtract(start_time)
       Console.WriteLine(elapsed_time.TotalSeconds.ToString("0.000000"))
       start_time = Now
       
       For i = 1 To TRIALS
            
       Next i
       stop_time = Now
       elapsed_time = stop_time.Subtract(start_time)
       Console.WriteLine(elapsed_time.TotalSeconds.ToString("0.000000"))   
   End Sub

End Class


      </source>


Date Time Subtraction

<source lang="vbnet"> Imports System Public Class MainClass

   Shared Sub Main(ByVal args As String())
       Dim date1 As Date = #7/20/2004#
       Dim date2 As Date = #8/7/2004#
       Dim elapsed_time As TimeSpan
       elapsed_time = Date.op_Subtraction(date2, date1)
       Console.WriteLine(elapsed_time.Days.ToString)
         
   End Sub

End Class


      </source>


Multiply Time Span

<source lang="vbnet"> Imports System Public Class MainClass

   Shared Sub Main(ByVal args As String())
       Dim ts1, ts2 As TimeSpan
       ts1 = New TimeSpan(1, 2, 3)
       ts2 = New TimeSpan(ts1.Ticks * 12)
       Console.WriteLine(ts1.ToString)
       Console.WriteLine(ts2.ToString)
         
   End Sub

End Class


      </source>