Handles子句需要在包含类型或其基类型之一中定义的WithEvents变量吗？

Question

当我在Visual Studio 2013中运行以下代码时，它显示：

Handles clause requires a WithEvents variable defined in the containing type or one of its base types

Private Sub Application_DocumentBeforeSave(ByVal Doc As Word.Document, ByRef SaveAsUI As Boolean, _
    ByRef Cancel As Boolean) Handles Application.DocumentBeforeSave
    Doc.Paragraphs(1).Range.InsertParagraphBefore()
    Doc.Paragraphs(1).Range.Text = "This text was added by using code." 
End Sub

谁能告诉我如何解决这个问题？ 上面的代码来自https://msdn.microsoft.com/en-us/library/cc442946.aspx

Answer 1

该代码假定当前类具有Application类型Microsoft.Office.Interop.Word.Application的字段（包括DocumentBeforeSave事件）

1. 创建新的Word 2013加载项项目
2. 打开ThisAddin.vb文件
3. 请注意，此类还有ThisAddin.Designer.vb中定义的部分类，其中声明了Application字段：

Friend WithEvents Application As Microsoft.Office.Interop.Word.Application