Vb.net 上下文菜单问题

在列表框中有一些空白……在列表框中选择项目时，它会正确显示上下文菜单，但如果项目选择了项目并单击列表框中的任意位置，它会显示上下文菜单

我的要求是，在选择项目时，仅在选择项目的适当位置显示contexmenu

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提前感谢……

私有子LStreentDocs\u MouseUp\u 1（ByVal发送者作为系统。对象，ByVal e作为 System.Windows.Forms.MouseEventArgs）处理lstreentdocs.MouseUp

Private Sub lstrecentdocs_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lstrecentdocs.SelectedIndexChanged

    If lstrecentdocs.SelectedIndex = -1 Then
        lstrecentdocs.ContextMenuStrip = Nothing
    Else
        lstrecentdocs.ContextMenuStrip = ContextMenuStrip2
    End If
End Sub

    Try
        If e.Button = Windows.Forms.MouseButtons.Right Then
            Dim index = lstrecentdocs.IndexFromPoint(e.Location)
            If index >= 0 Then
                lstrecentdocs.SelectedIndex = index
                ContextMenuStrip2.Show(lstrecentdocs, e.Location)
            Else
                ContextMenuStrip2.Visible = False
            End If
        End If
    Catch ex As Exception
        MsgBox(ex.Message)
    End Try       
End Sub