如何修复两个涉及时间的文本框之和的负数

Question

我有一个用户窗体，其中有两个文本框，用户在其中输入停机时间并将其放入列表框中，现在在同一个用户窗体中，我有另一个禁用的文本框，显示这两个文本的所有数字的总和（以分钟为单位）有时，代码运行良好，问题在于例如：用户在“txtTStart”文本框中输入 2300，在“txtTEnd”中输入 0010，它会带来 -1370 数字。我的问题是我怎样才能得到这个方法的正确总和。

Private Sub cmdNext_Click()

Dim x As Integer
Dim totaldt As Double
Dim r As Long
Dim tdt As Double
Dim tdtt As Double

If Trim(Me.txtTStart.Value) = "" Then
    Me.txtTStart.SetFocus
    MsgBox "Please Enter Time Start"
    Exit Sub
End If
If Trim(Me.txtTEnd.Value) = "" Then
    Me.txtTEnd.SetFocus
    MsgBox "Please Enter Time End"
    Exit Sub
End If
If Trim(Me.cmbCode.Value) = "" Then
    Me.cmbCode.SetFocus
    MsgBox "Please Enter Downtime Code"
    Exit Sub
End If
If Trim(Me.txtDesc.Value) = "" Then
    Me.txtDesc.SetFocus
    MsgBox "Please Enter Downtime Description"
    Exit Sub
End If
If Trim(Me.txtDesc.Value) = "INVALID DOWNTIME CODE" Then
    Me.txtDesc.SetFocus
    MsgBox "Please Insert Valid Downtime Code"
    Exit Sub
End If

    tdt = Format((CDate(txtTEnd.Value) - CDate(txtTStart.Value)) * 1440)

tdtt = Round(tdt)

x = lstDes.ListCount

With lstDes
         .AddItem
         .List(x, 0) = txtTStart.Value
         .List(x, 1) = txtTEnd.Value
         .List(x, 2) = tdtt
         .List(x, 3) = cmbCode.Value
         .List(x, 4) = txtDesc.Value

End With

totaldt = 0
With lstDes
    For r = 0 To .ListCount - 1
        totaldt = totaldt + .List(r, 2)
    Next r
End With

txtDT.Value = totaldt


Me.txtTStart.Value = ""
Me.txtTEnd.Value = ""
'Me.txtTot.Value = ""
Me.cmbCode.Value = ""
Me.txtDesc.Value = ""

End Sub

Answer 1

请将此行：if tdt<0 then tdt=tdt+1440 添加到您的代码行之后：

tdt = Format((CDate(txtTEnd.Value) - CDate(txtTStart.Value)) * 1440)