arrays - Visual Basic 6 运行时错误 381 "Invalid Property Array Index"

Question

我是编程的菜鸟，尤其是在 Visual Basic 中。我只使用 VB6，因为我必须在大学里使用它，我完全被卡住了。

我有一个列表框，我想在其中显示 radio 的名称，然后当我单击该名称时，我希望它将数据放入一些文本框中，这很简单，我知道但我什至不完全了解 VB6 语法，所以我我完全卡住了我问过我的老师，但他真的没有任何帮助。

这是我单击调试时突出显示的行:

x = radCatList.ItemData(radCatList.ListIndex)

这是整个表单的代码，同样它非常简单，我几乎不知道我在做什么这个项目的大部分是复制和粘贴工作:

Option Explicit

Private Sub Form_Load()
Dim r As radioRec
Dim radioChan As Integer
Dim x As Integer

x = 1
radioChan = FreeFile
Open radioFile For Random As radioChan Len = radioLen
Get radioChan, x, r
Do While Not EOF(radioChan)
    radCatList.AddItem r.rModel
    radCatList.ItemData(radCatList.NewIndex) = x
    x = x + 1
    Get radioChan, x, r
Loop
Close radioChan
End Sub

Private Sub radCatList_Click()
Dim r As radioRec
Dim radioChan As Integer
Dim x As Integer

radCatList.Clear

x = radCatList.ItemData(radCatList.ListIndex)
radioChan = FreeFile
Open radioFile For Random As radioChan Len = radioLen
Get radioChan, x, r
channelTxt = r.rLicense
licenseTxt = r.rLicense
rangeTxt = r.rRange
stockTxt.Text = r.rStock
Close radioChan
End Sub

Answer 1

您的 listindex 可能是 -1，因为还没有选择 listitem 吗？

看看下面的代码

'1 form with
'    1 listbox : name=List1
Option Explicit

Private Sub Form_Load()
  Dim intIndex As Integer
  For intIndex = 0 To 10
    List1.AddItem CStr(intIndex)
    List1.ItemData(intIndex) = intIndex * intIndex
  Next intIndex
  ShowData List1.ListIndex
End Sub

Private Sub Form_Resize()
  List1.Move 0, 0, ScaleWidth, ScaleHeight
End Sub

Private Sub List1_Click()
  ShowData List1.ListIndex
End Sub

Private Sub ShowData(intIndex As Integer)
  Dim strShow As String
  strShow = "Index:" & CStr(intIndex)
  If intIndex > -1 Then
    strShow = strShow & " Data:" & CStr(List1.ItemData(intIndex))
  End If
  Caption = strShow
End Sub

所以你所要做的就是检查 listindex 是否不是 -1