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我试图弄清楚如何在文本框中获取一个值（价格），该值与一个临时变量和一个数组一起放在那里，并将其更改为十进制值，以便我可以总结总销售额然后总结使用相同数组的另一个文本框的总重量。我已经用这个工作了大约 5 个小时，用我的书和搜索在线网站，但没有任何工作。我被困在私人子购买按钮程序中（倒数第二个）。我的项目总数计数器正在工作，我还制作了 subTotal Decimal 和 totalWeightDecimal 计数器，以确保消息框正常工作，但我想将 += 1 更改为正确的代码，但我找不到它。我尝试了解析，但没有成功。更改 textbox.text 我包含了我的整个代码供某人查看。我知道我有太多私有变量，只是在我摆脱它们之前等着弄清楚一切。任何帮助将不胜感激。总而言之，在整个程序中，我至少花费了 15 个小时。感谢您的时间和精力。

'Declare Item Structure.
Structure Item
    Dim upcString As String
    Dim nameString As String
    Dim descriptionString As String
    Dim weightString As String
    Dim priceDecimal As Decimal
End Structure

'Declare the ItemPrices Structure
Public Structure ItemPrices
    Dim itemdescriptionString As String
    Dim itempriceDecimal As Decimal
    Dim itemweightDecimal As Decimal
    Dim itemupcInteger As Integer
End Structure

Public Class lab7Form
    Private price1Decimal As Decimal
    Private subTotalDecimal As Decimal
    Private grandTotalDecimal As Decimal
    Private totalDecimal As Decimal
    Private totalItemsInteger As Integer
    Private MessageString As String
    Private totalWeightDecimal As Decimal

    Dim myItem As Item
    Private ItemPricesArray(3) As ItemPrices

    Private Sub exitButton_Click(sender As System.Object, e As System.EventArgs) Handles exitButton.Click
        If MsgBox("Click Yes to Exit, Click No to Cancel", MsgBoxStyle.YesNo, "You Decide") = MsgBoxResult.Yes Then
            Me.Close()
        End If
    End Sub

    Private Sub clearButton_Click(sender As System.Object, e As System.EventArgs) Handles clearButton.Click
        'Clear the textbox values.
        upcTextBox.Text = ""
        descriptionTextBox.Text = ""
        weightTextBox.Text = ""
        priceTextBox.Text = ""
    End Sub

    Private Sub lab7Form_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        'Load my itemsListbox with the items for the user.
        itemsListBox.Items.Add("Notebook PC")
        itemsListBox.Items.Add("Deskjet Printer")
        itemsListBox.Items.Add("Color Ink Cartridge")
        itemsListBox.Items.Add("Black Ink Cartridge")

        'Load the ItemPricesArray values. 
        ItemPricesArray(0).itemdescriptionString = "Notebook PC"
        ItemPricesArray(1).itemdescriptionString = "Deskjet Printer"
        ItemPricesArray(2).itemdescriptionString = "Color Ink Cartridge"
        ItemPricesArray(3).itemdescriptionString = "Black Ink Cartridge"

        ItemPricesArray(0).itempriceDecimal = 1500D
        ItemPricesArray(1).itempriceDecimal = 430D
        ItemPricesArray(2).itempriceDecimal = 11D
        ItemPricesArray(3).itempriceDecimal = 10D

        ItemPricesArray(0).itemweightDecimal = 7D
        ItemPricesArray(1).itemweightDecimal = 16D
        ItemPricesArray(2).itemweightDecimal = 0.5D
        ItemPricesArray(3).itemweightDecimal = 0.5D

        ItemPricesArray(0).itemupcInteger = 111111111
        ItemPricesArray(1).itemupcInteger = 222222222
        ItemPricesArray(2).itemupcInteger = 333333333
        ItemPricesArray(3).itemupcInteger = 444444444
    End Sub

    Private Sub itemsListBox_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles itemsListBox.SelectedIndexChanged
        descriptionTextBox.Text = itemsListBox.Text
        'I am using a table lookup   Do/Loop here.
        Dim myBoolean As Boolean        'True = I found an items price.
        Dim indexInteger As Integer = 0
        Do Until myBoolean Or indexInteger > 3
            With Me
                If .descriptionTextBox.Text = ItemPricesArray(indexInteger).itemdescriptionString Then
                    .priceTextBox.Text = ItemPricesArray(indexInteger).itempriceDecimal.ToString("C")
                    .weightTextBox.Text = ItemPricesArray(indexInteger).itemweightDecimal.ToString()
                    .upcTextBox.Text = ItemPricesArray(indexInteger).itemupcInteger.ToString()
                    myBoolean = True
                Else
                    indexInteger += 1
                End If
            End With
        Loop
    End Sub

    Private Sub purchaseButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles purchaseButton.Click
         Dim DecNumber1 As Decimal
        'Parse Numbers 
        DecNumber1 = Decimal.Parse(priceTextBox.Text)

        If purchaseButton.Enabled And priceTextBox.Text <> "" Then
            'Calculate the quantities
            totalItemsInteger += 1  'I can't figure out how to total up the weights and prices when they are both local variables.
            subTotalDecimal += DecNumber1
            totalWeightDecimal += 1

            'From Page 172 Put together what you want to appear in message boxes
            Dim MessageString As String
            Dim totalString As String
            Dim numberOfItemsString As String
            Dim weightOfItemsString As String

            numberOfItemsString = totalItemsInteger.ToString()
            totalString = subTotalDecimal.ToString("C")
            weightOfItemsString = totalWeightDecimal.ToString("N")

            MessageString = "Total Items : " & numberOfItemsString &
                Environment.NewLine & "Total Weight: " & weightOfItemsString &
                Environment.NewLine & "Subtotal: " & totalString

            'Display the message box
            MessageBox.Show(MessageString, "Items Purchased", MessageBoxButtons.OKCancel)
        End If
    End Sub

    Private Sub totalButton_Click(sender As System.Object, e As System.EventArgs) Handles totalButton.Click
        Dim numberofOrdersString As String
        If totalButton.Enabled Then
            numberofOrdersString = "Number of Orders:  " & totalItemsInteger.ToString()
            MessageString = "Total Sales:  " & grandTotalDecimal.ToString("C")

            'Display the message box
            MessageBox.Show(MessageString, "Items Purchased", MessageBoxButtons.OKCancel)
        End If
    End Sub
End Class
4

3 回答 3

1

您需要遍历数组ItemPrices对象数组，如下所示：

Dim itempriceDecimalTotal As Decimal
Dim itemweightDecimalTotal As Decimal

For Each theItemPrices As ItemPrices In ItemPricesArray
    itempriceDecimalTotal += theItemPrices.itempriceDecimal
    itemweightDecimalTotal += theItemPrices.itemweightDecimal
Next

现在您可以将值转换为字符串，如下所示：

Dim MessageString As String
Dim totalString As String
Dim numberOfItemsString As String
Dim weightOfItemsString As String

numberOfItemsString = totalItemsInteger.ToString()
totalString = itempriceDecimalTotal.ToString("C")
weightOfItemsString = itemweightDecimalTotal.ToString("N")

最后，您可以在消息框中显示总值，如下所示：

MessageString = "Total Items : " & numberOfItemsString &
        Environment.NewLine & "Total Weight: " & weightOfItemsString &
        Environment.NewLine & "Subtotal: " & totalString

'Display the message box
MessageBox.Show(MessageString, "Items Purchased", MessageBoxButtons.OKCancel)
于 2013-10-10T02:22:32.963 回答
0 
Dim priceTotal As Double = (From itemPrice in ItemPricesArray
                            Select itemPrice.itempriceDecimal).Sum

Dim weightTotal As Double = (From itemPrice in ItemPricesArray
                             Select itemPrice.itemweightDecimal).Sum
于 2013-10-10T03:10:27.593 回答
0

获取数组中项目的任何属性的总数是利用 LINQ 扩展方法 Sum 的简单问题：

Dim grandtotal As Double = ItemPricesArray.Sum(Function(x) x.itempriceDecimal)

然后使用 ToString() 方法显示为字符串效果很好：

Textbox1.Text = grandtotal.ToString("C2")'display as currency with 2 decimal places
于 2013-10-10T02:55:39.137 回答