vb.net开发中使用excel插件的代码

以下是引用片段：
　　Public Class ConnectClass Connect
　　Implements Extensibility.IDTExtensibility2
　　Dim app As Excel.Application
　　Dim wb As Excel.Workbook
　　Dim ws As Excel.Worksheet
　　Dim addInInstance As Object
　　Dim pasteText As Microsoft.Office.Core.CommandBarButton ‘定义一个工具栏按钮
　　Public Sub OnBeginShutdown()Sub OnBeginShutdown(ByRef custom As System.Array) Implements Extensibility.IDTExtensibility2.OnBeginShutdown
　　End Sub
　　Public Sub OnAddInsUpdate()Sub OnAddInsUpdate(ByRef custom As System.Array) Implements Extensibility.IDTExtensibility2.OnAddInsUpdate
　　End Sub
　　Public Sub OnStartupComplete()Sub OnStartupComplete(ByRef custom As System.Array) Implements Extensibility.IDTExtensibility2.OnStartupComplete
　　End Sub
　　Public Sub OnDisconnection()Sub OnDisconnection(ByVal RemoveMode As Extensibility.ext_DisconnectMode, ByRef custom As System.Array)
　　Implements Extensibility.IDTExtensibility2.OnDisconnection
　　End Sub
　　Public Sub OnConnection()Sub OnConnection(ByVal application As Object, ByVal connectMode As Extensibility.ext_ConnectMode,
　　ByVal addInInst As Object, ByRef custom As System.Array)
　　Implements Extensibility.IDTExtensibility2.OnConnection
　　If TypeOf (application) Is Excel.Application Then app = CType(application, Excel.Application)
　　addInInstance = addInInst
　　wb = app.ActiveWorkbook
　　ws = CType(wb.ActiveSheet, Excel.Worksheet)
　　Dim toolbar As Microsoft.Office.Core.CommandBar = Nothing
　　If Not app Is Nothing Then
　　toolbar = AddToolbar(app, "专用工具栏") ’添加工具栏
　　End If
　　’ 建立按钮添加文本
　　pasteText = MakeANewButton(toolbar, "Insert text",
　　1044, AddressOf pasteText_Click) ’添加工具栏按钮并帮定事件
　　End Sub
　　’添加工具栏
　　Private Function AddToolbar()Function AddToolbar(ByVal ex As Excel.Application, _
　　ByVal toolbarName As String) As Microsoft.Office.Core.CommandBar
　　Dim toolBar As Microsoft.Office.Core.CommandBar = Nothing
　　Try
　　’ 为add-in建立一个命令条
　　toolBar = CType(ex.CommandBars.Add(toolbarName,
　　Microsoft.Office.Core.MsoBarPosition.msoBarTop, , True),