Visual Basic调用子程序后如何禁用列表框后续输入

你只需要在双击事件的逻辑执行完成后，将所有列表框的Enabled属性设置为False即可禁用后续所有输入，修改后的代码如下：

Public Sub LstAnswer4_MouseDoubleClick(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles lstAnswer4.MouseDoubleClick
    If res4 = 2 Then
        MsgBox("correct")
        Score = Score + 1
        ListBox1.Items.Clear()
        Dim displayscore As Object
        displayscore = (Score & " out of " & outof)
        ListBox1.Items.Add(displayscore)
    Else 
        MsgBox("wrong")
    End If
    ' 禁用所有列表框，替换为你实际的4个列表框控件名即可
    lstAnswer1.Enabled = False
    lstAnswer2.Enabled = False
    lstAnswer3.Enabled = False
    lstAnswer4.Enabled = False
    ' 若需要保留ListBox1的操作可注释下一行
    ListBox1.Enabled = False
End Sub

优化建议 #

如果其余3个列表框也绑定了双击事件，你可以把禁用逻辑封装成通用子过程，避免重复写代码：

' 定义通用禁用方法
Private Sub DisableAllAnswerListBoxes()
    lstAnswer1.Enabled = False
    lstAnswer2.Enabled = False
    lstAnswer3.Enabled = False
    lstAnswer4.Enabled = False
    ListBox1.Enabled = False
End Sub

在每个列表框的双击事件最后调用即可：

Call DisableAllAnswerListBoxes()

可选方案（不禁用控件外观，仅屏蔽操作） #

如果你不想让列表框变灰，只需要屏蔽后续的双击响应，可以在窗体类中声明一个标记变量：

' 窗体类级别变量，标记是否已经完成作答
Dim isAnswered As Boolean = False

然后在每个双击事件开头先判断标记，作答完成后修改标记：

Public Sub LstAnswer4_MouseDoubleClick(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles lstAnswer4.MouseDoubleClick
    ' 已经作答过直接退出，不执行后续逻辑
    If isAnswered Then Exit Sub

    If res4 = 2 Then
        MsgBox("correct")
        Score = Score + 1
        ListBox1.Items.Clear()
        Dim displayscore As Object
        displayscore = (Score & " out of " & outof)
        ListBox1.Items.Add(displayscore)
    Else 
        MsgBox("wrong")
    End If

    ' 修改标记，后续所有双击事件都不会响应
    isAnswered = True
End Sub

内容的提问来源于stack exchange，提问作者Quizlet23