Vb.Net阵列帮助!!!! [英] Vb.Net Array Help!!!!

问题描述

我真的需要有人帮助这个项目，因为截止日期是明天！ （我知道它有点晚了！）提前谢谢。



我正在尝试在vb.net中编写一个数组来保存记录位置的信息从几个列表框到.dat文件中的数组。我的问题是数据不会保存，我不断收到此错误：对象引用未设置为对象的实例在.JuiceID（i）

这是数组的代码：

Hi, I really need someones help on this project as the deadline is for tomorrow! (I left it a bit late I know!) Thanks in advance.

I'm trying to code an array in vb.net to save information at a record position from several listboxes into an array in a .dat file. My problem is the data will not save, and I keep getting this error: Object reference not set to an instance of an object at .JuiceID(i)
This is the code for the array:

For i = 0 To lstJuiceID.Items.Count - 1
                With OrderItems
                .JuiceID(i) = lstJuiceID.Items.Item(i)
                .JuiceName(i) = lstJuiceName.Items.Item(i)
                .Quantity(i) = lstQuantity.Items.Item(i)
                .Total(i) = lstTotal.Items.Item(i)
                .UnitPrice(i) = lstUnitPrice.Items.Item(i)
                End With
            OrderItems.CustomerID = lblID.Text
            OrderItems.OrderNumber = lblOrderNumber.Text
        Next
        
        FileOpen(3, "OrderItems.dat", OpenMode.Random, , , Len(OrderItems))
        RecordPosition = LOF(3) / Len(OrderItems)
        RecordPosition = RecordPosition + 1
        FilePut(3, OrderItems, RecordPosition)
        FileClose(3)

        MsgBox("Order Saved!") 'tells the user the order has been saved

这是OrderItems数据结构的代码：

and this is the code for the OrderItems Data Structure:

Module OrderItems
    Public Structure OrderItemType
        <VBFixedString(5)> Dim CustomerID As String
        <VBFixedString(6)> Dim OrderNumber As String
        <VBFixedString(6)> Dim JuiceID() As String
        <VBFixedString(20)> Dim JuiceName() As String
        Dim UnitPrice() As String
        Dim Quantity() As String
        Dim Total() As String
    End Structure
End Module

你能帮助我吗？谢谢！

Can you help me? Thanks!

推荐答案

请阅读我对这个问题的评论。



你差不多完成了，试着完成它。看看这里：

结构和其他编程元素（Visual Basic） [ ^ ]

结构数组 [ ^ ]



它应该可以帮助您找到解决方案。

Please, read my comment to the question.

You're almost done, try to finish it. Have a look here:
Structures and Other Programming Elements (Visual Basic)[^]
Array of Structure[^]

It should help you to find solution.

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