ListBox IndexOutOfRangeException未处理OnClick [英] ListBox IndexOutOfRangeException was unhandled OnClick
问题描述
我在使用ListBox时遇到了奇怪的情况。
在一个模块中,我用一个名字来填充一个ListBox一份文件。在表单上,ListBox显示2个项目。
Hi,
I am having for a weird situation with a ListBox.
In a Module I fill a ListBox with names from a file. On the Form the ListBox shows 2 Items.
If File.Exists(fUsers) Then
With frmSettings
Dim NoLines As Integer = File.ReadAllLines(fUsers).Length ' Antal linier i filen
Dim lNames As New List(Of String)
Dim lPass As New List(Of String)
For i = 1 To NoLines - 1 Step 2
lNames.Add(Crypto.Decrypt(File.ReadAllLines(fUsers).ElementAtOrDefault(i), skey))
Next i
For i = 2 To NoLines - 1 Step 2
lPass.Add(Crypto.Decrypt(File.ReadAllLines(fUsers).ElementAtOrDefault(i), skey))
Next
For i = 0 To lNames.Count - 1
pList.Add(New Users(lNames(i), lPass(i)))
.lstUsers.Items.Add(lNames(i))
Next
End With
End If
单击ListBox时,第一个名称显示正确。第二个名称给出了错误:
IndexOutOfRangeException未处理 - 索引超出了数组的范围
Private Sub lstUsers_Click(sender As Object, e As System.EventArgs) Handles lstUsers.Click
If lstUsers.Items.Count > 0 Then
Debug.Print(CStr(lstUsers.SelectedIndex))
Debug.Print(CStr(lstUsers.Items.Count))
txtUser.Text = lstUsers.SelectedItems.Item(lstUsers.SelectedIndex).ToString
End If
End Sub
调试显示计数中的2项
单击时调试显示正确的索引
提前谢谢,
Henrik
Debug shows 2 items in count
When clicked Debug shows the correct Index
Thank you in advance,
Henrik
推荐答案
你的错误是这样的:
Your error is in this:
lstUsers.SelectedItems.Item(lstUsers.SelectedIndex).ToString
你只有一个选中的项目(点击一个) - 除非你多选,你应该总是有0而不是lstUsers.Selecte dIndex甚至在多选时,除非你选择所有项目,否则会在某些时候中断。
或者使用完整列表选择所选项:
You have only 1 selected item (which is the one clicked) - unless you're multiselecting you should always have 0 instead of lstUsers.SelectedIndex and even when multiselecting, unless you select ALL items this will break at some point.
Or alternatively use full list to select the one selected:
lstUsers.Items.Item(lstUsers.SelectedIndex).ToString
如果这有帮助,请花时间接受解决方案。谢谢。
If this helps, please take time to accept the solution. Thank you.
这篇关于ListBox IndexOutOfRangeException未处理OnClick的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!