用CefSharp.WinForms下载。

Question

我使用CefSharp在我的应用程序中加入了一个网络浏览器，但是当我添加了DownloadHandler.vb(从C#翻译成VB)时，我遇到了这个问题。

' Copyright © 2013 The CefSharp Authors. All rights reserved.
'
' Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.

Imports System
Imports CefSharp

Namespace CefSharp.Example.Handlers
    Public Class DownloadHandler
        Inherits IDownloadHandler

        Public Event OnBeforeDownloadFired As EventHandler(Of DownloadItem)
        Public Event OnDownloadUpdatedFired As EventHandler(Of DownloadItem)

        Public Sub OnBeforeDownload(ByVal chromiumWebBrowser As IWebBrowser, ByVal browser As IBrowser, ByVal downloadItem As DownloadItem, ByVal callback As IBeforeDownloadCallback)
            RaiseEvent OnBeforeDownloadFired(Me, downloadItem)

            If Not callback.IsDisposed Then

                Using callback
                    callback.Continue(downloadItem.SuggestedFileName, showDialog:=True)
                End Using
            End If
        End Sub

        Public Sub OnDownloadUpdated(ByVal chromiumWebBrowser As IWebBrowser, ByVal browser As IBrowser, ByVal downloadItem As DownloadItem, ByVal callback As IDownloadItemCallback)
            RaiseEvent OnDownloadUpdatedFired(Me, downloadItem)
        End Sub
    End Class
End Namespace

所以我出现了 "类只能继承其他类 "的错误（我是法国人，所以我的Visual Studio是法语，我怎么翻译都可以，抱歉英语不好；）），在Form1.vb中我看到了这个错误。

'Cef'不是WindowsApp1.CefSharp的成员。

如果我删除DownloadHandler.vb，这个错误就会消失，请帮助我。