Visual Studio for Application 内幕之四（转载）

Visual Studio for Application 内幕之四

除了HostObject,vsa还有一个利于开发的特性，Event source Object(怎么翻译，提供事件的对象)

重点

首先，我们需要明确Event Source Object是通过IVsaCodeItem接口的AddEventSource来增加到脚本中，在运行时，则通过其IVsaSite的GetEventSourceInstance来获取，而事件过程的定制，则是通过vsa Ide实现

希望下面的讲解有助于大家理解这个过程，在这个过程中，我们用到了许多hostObject节的代码

准备

1、我们在document类中增加一个事件和方法

    Public Event BeforeSave(ByRef Cancel As Boolean)
    Public Sub Save()
        Dim blnCancel As Boolean

        RaiseEvent BeforeSave(blnCancel)
        If Not blnCancel Then
            System.Windows.Forms.MessageBox.Show("保存文档")
        Else
            System.Windows.Forms.MessageBox.Show("不保存文档")
        End If

    End Sub

2、编译
vbc document.vb /t:library /out:bin\document.dll /r:system.windows.forms.dll

3、在项目中引用document.dll

4、定位到MyVsaSite 类，增加一个SaveDocument过程

Public Sub SaveDocument()
        doc.Save()

    End Sub

5、定位到MyVsaSite类,实现GetEventSourceInstance方法
这里itemName 是下面我们所要讲到的IVsaCodeItem 的名称,eventSourceName则是IVsaCodeItem.AddEventSource的第一个参数
  Public Function GetEventSourceInstance(ByVal itemName As String, ByVal eventSourceName As String) As Object Implements Microsoft.Vsa.IVsaSite.GetEventSourceInstance
        Select Case itemName.ToLower & "+" & eventSourceName.ToLower
            Case "test+hostobject"
                Return doc
        End Select
    End Function

下面我们来描述重点

如何增加一个Event Source Object到script中
IVsaCodeItem的AddEventSource方法

该方法需要两个参数，一个是在脚本中使用的Event Source Object名，一个是其类型名，在我们这个例子中，我们把对象名命名为HostObject，类型名，当然是Document了
   Dim codeItem As VsaCodeItem
        codeItem = m_VsaEngine.Items.CreateItem("test", Microsoft.Vsa.VsaItemType.Code, Microsoft.Vsa.VsaItemFlag.Class)
   codeItem.AddEventSource("HostObject", "Document")

在运行时获取Event soruce Object的实例

见上

然后，我们通过vsa ide，为这个事件过程增加代码

 
大家可以看到vsa 自动生成的声明
Public WithEvents HostObject as Document
和我们添加的部分

保存我们的代码，同代码同内幕2的一致

If m_VsaEngine.Compile() Then

            Dim pe() As Byte
            Dim pdb() As Byte
            m_VsaEngine.SaveCompiledState(pe, pdb)

            Dim fs As New FileStream("c:\test.dll", FileMode.Create)
            Dim bs As New BinaryWriter(fs)
            bs.Write(pe)
            fs.Close()
            bs.Close()
            fs = New FileStream("c:\test.pdb", FileMode.Create)
            bs = New BinaryWriter(fs)
            bs.Write(pdb)
            fs.Close()
            bs.Close()
        End If

运行

m_VsaEngine = New Microsoft.Vsa.VsaLoader
        m_VsaEngine.RootNamespace = "test"
        m_VsaEngine.RootMoniker = "test://project1"
        Dim mysite As New MyVsaSite
        m_VsaEngine.Site = mysite
        m_VsaEngine.Run()

    
        mysite.SaveDocument()

看看是否出现我们需要的结果

在这个例子中，我们使用vsa sdk中提供的Microsoft.VisualBasic.Vsa.Dt.dll，来显示vsa的Ide，我们将在以后来介绍如何显示vsa的ide，以下是我们这个例子中的代码
 

Dim mySite As Microsoft.Vsa.IVsaSite
        mySite = New MyVsaSite

        m_VsaEngine = New Microsoft.VisualBasic.Vsa.Dt.VsaEngine
        m_VsaEngine.Name = "Engine1"

        With m_VsaEngine
            .RootNamespace = "test"
            .RootMoniker = "test://project1"
            .Site = mySite
        End With
        m_VsaEngine.InitNew()

        Dim ReferenceItem As Microsoft.Vsa.IVsaReferenceItem
        ReferenceItem = m_VsaEngine.Items.CreateItem("Document", Microsoft.Vsa.VsaItemType.Reference, Microsoft.Vsa.VsaItemFlag.None)

        ReferenceItem.AssemblyName = "C:\Documents and Settings\Administrator\My Documents\Visual Studio Projects\WindowsApplication2\WindowsApplication2\bin\Document.Dll"
        Dim codeItem As VsaCodeItem
        codeItem = m_VsaEngine.Items.CreateItem("test", Microsoft.Vsa.VsaItemType.Code, Microsoft.Vsa.VsaItemFlag.Class)
        codeItem.AddEventSource("HostObject", "Document")
        m_VsaDTEngine = CType(m_VsaEngine, Microsoft.Vsa.IVsaDTEngine)

        m_VsaDTEngine.InitCompleted()
        m_Ide = m_VsaDTEngine.GetIDE
        m_Ide.Site = mySite

        If m_VsaEngine.Compile() Then

            Try
                m_Ide.ShowIDE(True)
            Catch ex As Exception
                Debug.WriteLine(ex)

            End Try
        End If