Question

我正在创建一个 POS系统，在小计页面上我有各种标签，如'现金'，'卡'，'凭证'等。

比如说客户总数达到20英镑，他们想用现金支付10英镑，而另外10英镑用他们的卡支付，我有问题让标签按照他们应该的总计。

'总投标'标签显示0.000，即使它应该说£20.00并且余额和更改标签总是显示0.00，即使他们应该说其他。我知道这是非常基本的，但我现在已经尝试了很多年，而且我无处可去。

我也试过从数据库中调用值，但也没有喜欢。谢谢。（我只包含一个付款按钮点击事件，因为它们都是相同的，除了标签名称更改，例如lblcash.text会在卡片点击事件中说lblcard.text。）

Private Sub btnCash_Click(sender As Object, e As EventArgs) Handles btnCash.Click

    'Payment methods...........??
    '2 cash entries
    'cash and card
    'gift voucher and cash
    'gift voucher and card

    If txtCash.Text = "" Then
        MessageBox.Show("Please enter amount")
    ElseIf txtCash.Text >= "0.00" Then

        lblCash.Text = txtCash.Text
        lblCash.Text = FormatCurrency(lblCash.Text, 2)

        lblTotTend.Text = (lblCash.Text) + (lblCredit.Text) + (lblVoucher.Text) + (lblOther.Text)
        lblTotTend.Text = FormatCurrency(lblTotTend.Text, 2)

        'DISPLAYING AS £0.00
        lblBALANCE.Text = (lblTOTALDUE.Text) - (lblTotTend.Text)
        lblBALANCE.Text = FormatCurrency(lblBALANCE.Text, 2)

        If lblBALANCE.Text < "0.00" Then
            lblBALANCE.Text = "£0.00"
        End If

        lblChange.Text = (lblTotTend.Text) - (lblTOTALDUE.Text)
        lblChange.Text = FormatCurrency(lblChange.Text, 2)

        If lblChange.Text <= "£0.00" Then
            lblChange.Text = "£0.00"
        End If

        txtCash.Text = ""

        SqlStr = "UPDATE Subtotal SET CASH = '" & lblCash.Text & "'"
        With CMD
            .Connection = CN
            .CommandType = CommandType.Text
            .CommandText = SqlStr
        End With
        DataP = CMD.ExecuteScalar

        SqlStr = "UPDATE Subtotal SET CHANGE = '" & lblChange.Text & "'"
        With CMD
            .Connection = CN
            .CommandType = CommandType.Text
            .CommandText = SqlStr
        End With
        DataP = CMD.ExecuteScalar

        SqlStr = "UPDATE Subtotal SET BalanceRemain = '" & lblBALANCE.Text & "'"
        With CMD
            .Connection = CN
            .CommandType = CommandType.Text
            .CommandText = SqlStr
        End With
        DataP = CMD.ExecuteScalar

        SqlStr = "UPDATE Subtotal SET TotalTendered = '" & lblTotTend.Text & "'"
        With CMD
            .Connection = CN
            .CommandType = CommandType.Text
            .CommandText = SqlStr
        End With
        DataP = CMD.ExecuteScalar
    End If

    SqlStr = "INSERT INTO SalesLog(ReceiptID) SELECT Id FROM Subtotal"
    With CMD
        .Connection = CN
        .CommandType = CommandType.Text
        .CommandText = SqlStr
    End With
    DataP = CMD.ExecuteNonQuery

    SqlStr = "INSERT INTO TransactionLog(ReceiptID) SELECT Id FROM Subtotal"
    With CMD
        .Connection = CN
        .CommandType = CommandType.Text
        .CommandText = SqlStr
    End With
    DataP = CMD.ExecuteNonQuery

    ' Added this statement to try solve problem with totaltendered label
    SqlStr = "SELECT SUM(TotalTendered) FROM Subtotal"
    With CMD
        .Connection = CN
        .CommandType = CommandType.Text
        .CommandText = SqlStr
    End With
    lblTotTend.Text = CMD.ExecuteScalar
    lblTotTend.Text = FormatCurrency(lblTotTend.Text, 2)

    'UPDATES THE PRICE LABEL TEXTBOX WITH THE LATEST PRICE TOTAL WITHIN THE ACTIVE TABLE!!
    SqlStr = Nothing
    SqlStr = "SELECT SUM(Price) FROM Active"
    With CMD
        .Connection = CN
        .CommandType = CommandType.Text
        .CommandText = SqlStr
    End With
    lblTOTALDUE.Text = CMD.ExecuteScalar
    ' lblTOTALDUE.Text = FormatCurrency(lblTOTALDUE.Text, 2)

    If lblBALANCE.Text = "£0.00" Then
        Reset()
        Application.DoEvents()
        'TILL DRAWER OPEN
        Threading.Thread.Sleep(5000)
        Me.Close()
        Login.Show()
    End If

End Sub

Answer 1

好的......你正在尝试对字符串进行数学运算.. If lblChange.Text <= "£0.00" Then将无法按照您的预期运作。

我可以建议你的'价值'标签中没有货币符号，但是将它们放在一个单独的标签中，从长远来看这将有所帮助。如果您的应用程序走向国际化......或者我们采用欧元......你永远不会知道:)会发生什么？

使用货币符号，您需要做的就是将“价值”标签转换为双打，例如CDbl(lblChange.Text) - 确保它们首先不是空白。

标签根据其他标签中的值而变化

1 个答案: