Question

我真的很生气。我不明白为什么这个事件不断抛出一个空白错误。以下是我的代码。

Private Sub cboSections_SelectedChangeCommitted(sender As System.Object, e As System.EventArgs) Handles cboSections.SelectionChangeCommitted
    On Error GoTo EH

    If TypeOf sender Is Windows.Forms.ComboBox Then
        'some boolean that checks if we are skipping this event, thus it does if so
        If mbSkipEvent Then Exit Sub

        'checks if index that was changed to is > 0 then it toggles the bottom command buttons
        If cboSections.SelectedIndex > 0 Then
            ToggleCmdButtons(True)
        Else
            ToggleCmdButtons(False)
        End If

        'sets the string msPurpose
        msPurpose = "Show Section"
        Debug.Print("Im here")
    End If
EH:
    Debug.Print("Error Description: " & Err.Description)
End Sub

在我的输出中，我得到“错误描述：”。而已。如果任何人有任何解决方案或指向正确的方向，那就太棒了。

Answer 1

让我们尝试一些真正的错误处理，看看你是否有更好的东西。虽然我们正在努力，但我们可以稍微简化一下代码：

Private Sub cboSections_SelectedChangeCommitted(sender As System.Object, e As System.EventArgs) Handles cboSections.SelectionChangeCommitted
    Dim comboBox = TryCast(sender, ComboBox)
    If comboBox Is Nothing OrElse mbSkipEvent Then Exit Sub
    Try
       'checks if index that was changed to is > 0 then it toggles the bottom command buttons
       ToggleCmdButtons(cboSections.SelectedIndex > 0)

       'sets the string msPurpose
        msPurpose = "Show Section"
        Debug.Print("Im here")
    Catch Ex As Exception
        Debug.Print("Error Description: " & Ex.Message)
    End Try
End Sub

VB.Net SelectedChangeCommitted投掷错误

1 个答案: