時間減去錯誤

Question

這是我的代碼;

Option Strict On 

Public Class Form1 

Private Sub Form1_Load(sender As Object, e As System.EventArgs) Handles Me.Load 

    Dim Start As DateTime 
    Start = DateTime.Now 

    Threading.Thread.Sleep(22000) 

    If Date.Now.Subtract(Start).TotalMilliseconds < 28000 Then 
     Threading.Thread.Sleep(28000 - Date.Now.Subtract(Start).TotalMilliseconds) 
    End If 

End Sub 

End Class 

這裏是錯誤圖片;

http://4.1m.yt/L8KI8ST.png

Answer 1

Threading.Thread.Sleep可以將時間段作爲參數。

Dim Start As DateTime 
    Start = DateTime.Now 

    Threading.Thread.Sleep(22000) 

    Dim howlong As TimeSpan = TimeSpan.FromMilliseconds(Date.Now.Subtract(Start).TotalMilliseconds) 

    If howlong.TotalMilliseconds < 28000 Then 
     Threading.Thread.Sleep(TimeSpan.FromMilliseconds(28000 - howlong.TotalMilliseconds)) 
    End If 

Answer 2

這也可以在多一點閱讀的方式與時間跨度的和曾經計算差值，並與目標類轉換完成它。

Option Strict On 

Public Class Form1 

    Private Sub Form1_Load(sender As Object, e As System.EventArgs) Handles Me.Load 

     Dim Start As Date = Now 

     Threading.Thread.Sleep(New TimeSpan(0, 0, 22)) 

     Dim ElapsedSeconds As Int32 = CInt(Now.Subtract(Start).TotalSeconds) 

     If ElapsedSeconds < 28 Then 
      Threading.Thread.Sleep(New TimeSpan(0, 0, 28 - ElapsedSeconds)) 
     End If 

    End Sub 

End Class