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好的，所以我的累加器现在正在添加并正确显示在表格中。但是，我的 if...then 语句有问题，在达到 125 后它没有将其扔到第二级。我可以达到 125，我需要输入以启用我的按钮。任何帮助表示赞赏！

*编辑以显示使用 Do While 循环更新。现在导致我的输入错误 msgbox 出现问题... *

do while decTotalCredits < 125 
        If IsNumeric(txtCredit.Text) Then
            ' This statement will convert the string entered to decimal and establish the 
            ' input as the decCredit Variable
            decCredit = Convert.ToDecimal(txtCredit.Text)
            ' This Case Statement is to verify that the correct denominations of coins are 
            ' being entered in the machine. 
            Select Case decCredit
                Case 5, 10, 25, 100
                    ' This line adds the newly entered credit to the 
                    ' exsisting total
                    decTotalCredits += decCredit
                    lblTotal.Text = Convert.ToString(decTotalCredits)
                    lblTotal.Visible = True
                    ' reset the text input box for the credit amount
                    txtCredit.Clear()
                    txtCredit.Focus()
                Case Else
                    ' This message will appear if a Credit is entered that does not
                    ' conform to normal coins
                    MsgBox("Please enter a valid coin amount", , "Invalid Amount Entered")
            End Select
        Else
            ' This message will occur when a user inputs a non-numeric entry
            MsgBox("Please enter a valid Coin amount", , "Input Error")
        End If
    Loop

    ' Loop should complete when credits hit 125 and activate this code
    ' Once the credits are reached the prompt to make selection is visible. 
    lblMakeSelection.Visible = True
    ' Once the credits are reached, the buttons for selection become enabled.
    btnDietPepsi.Enabled = True
    btnPepsi.Enabled = True
    btnSierraMist.Enabled = True
    btnLemonade.Enabled = True
    btnDrPepper.Enabled = True
    btnWater.Enabled = True

End Sub
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1 回答 1

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从您给我们的代码中，它将进入循环，添加到总数，擦除 txtCredit 文本框，再次启动循环，然后显示错误消息框，因为 txtCredit 不再是数字。

假设逻辑在按钮单击或 TextBox Validate 例程中，建议您删除循环并在启用按钮之前添加“If decTotalCredit >= 125 Then”语句。

于 2012-04-13T03:07:34.657 回答