Question

我的问题是当我按下bigmacadd按钮和减号按钮时，bigmac正常工作。但是当我按下mcdouble添加按钮时，我得到了一堆数字。我如何才能使它显示2.50作为小数位？

Public Class Form1
    Const bigmac As Decimal = 4D
    Const mcdouble As Decimal = 2.25
    Dim tax As Decimal
    Dim price As Decimal
    Dim quantity As Integer
    Dim finaltotal As Decimal

    Private Sub Btnbigmacadd_Click(sender As Object, e As EventArgs) Handles Btnbigmacadd.Click
        quantity = quantity + 1
        txtquan.Text = quantity

        price += bigmac
        txtprice.Text = price

        tax = price * 0.15
        txttax.Text = tax

        finaltotal = price + tax
        txtfinaltotal.Text = finaltotal
    End Sub

    Private Sub btnbigmacminus_Click(sender As Object, e As EventArgs) Handles btnbigmacminus.Click
        quantity = quantity - 1
        txtquan.Text = quantity

        price -= bigmac
        txtprice.Text = price

        tax = price * 0.15
        txttax.Text = tax

        finaltotal = price + tax
        txtfinaltotal.Text = finaltotal
    End Sub

    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
        quantity = quantity + 1
        txtquan.Text = quantity

        price += mcdouble
        txtprice.Text = price

        tax = price * 0.15
        txttax.Text = tax

        finaltotal = price + tax
        txtfinaltotal.Text = finaltotal
     End Sub
End Class

Answer 1

您可以使用tax方法

将Math.Round舍入到两位小数

tax = Math.Round(price * 0.15D, 2)
txttax.Text = tax.ToString()

finaltotal = price + tax
txtfinaltotal.Text = finaltotal.ToString()

如果要在tax和finaltotal中保留额外的小数位数，但在文本框中只显示两位小数，则可以使用ToString("N2")方法。

tax = price * 0.15D
txttax.Text = tax.ToString("N2")

finaltotal = price + tax
txtfinaltotal.Text = finaltotal.ToString("N2")

我如何舍入双值？

1 个答案: