关于vb.net：我需要将textbox.text更改为十进制值以汇总总数并显示在消息框中。使用vb 2010

I need to change textbox.text into decimal value to sum up totals and display in message box. Using vb 2010

我试图弄清楚如何在文本框(价格)中获取一个值，该文本框带有一个临时变量和一个数组，然后将其更改为十进制值，这样我就可以得出总销售额和然后使用相同的数组对另一个文本框的总权重求和。我已经用书和搜索在线站点进行了大约5个小时的工作，但没有任何效果。我陷入了私人次级购买按钮的过程(从底部开始第二个)。我的total items计数器正在工作，并且我也创建了subTotal Decimal和totalWeightDecimal计数器，以确保消息框正在工作，但是我想将= 1更改为正确的代码，但我找不到它。我尝试了解析，但这是不行的。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，只是等我弄清楚所有东西之后再将它们清除掉。任何帮助将不胜感激。总而言之，我在整个程序上花了至少15个小时。感谢您的时间和精力。

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'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