在VB中将类对象序列化为字符串

有时候，我们需要把一个类对象序列化成字符串保存起来，或者通过网络传输给另一台机器，然后再异步或异地克隆出原来的类对象，比如ACCESS没有服务器端，而我们加它加了一个服务器代理程序，代理程序负责把查询出来的记录集传输给客户端，这时，我们可以遍历记录集内容，生成一个字符串传输给客户端，然后在客户端再加载记录集内容。其实，利用VB内置的类对象propertybag，我们还可以直接序列化记录集对象，传输给客户端后，客户端直接复制出该对象就可行，比遍历记录集的效率提高了N倍。

序列化的代码如下：

Option Explicit '* ************************************** * '* 模块<a href="https://www.jb51.cc/tag/mingcheng/" target="_blank" class="keywords">名称</a>：modStream.bas '* 模块<a href="https://www.jb51.cc/tag/gongneng/" target="_blank" class="keywords">功能</a>：序列化类对象为字符串 '* 作者：lyserver '* ************************************** * '- ----------------------------------- ' <a href="https://www.jb51.cc/tag/hanshu/" target="_blank" class="keywords">函数</a>说明：将类对象序列化为字符串 '- ----------------------------------- Function ObjectSav<a href="https://www.jb51.cc/tag/eto/" target="_blank" class="keywords">eto</a>String(objSource As Object,KeyName As String) As String Dim i As Long Dim objBag As New <a href="https://www.jb51.cc/tag/propertybag/" target="_blank" class="keywords">propertybag</a> Dim bytData() As Byte On Error Resume Next If objSource Is <a href="https://www.jb51.cc/tag/nothing/" target="_blank" class="keywords">nothing</a> Or Len(KeyName) = 0 Then Exit Function objBag.WriteProperty KeyName,objSource bytData = objBag.Contents For i = 0 To UBound(bytData) ObjectSav<a href="https://www.jb51.cc/tag/eto/" target="_blank" class="keywords">eto</a>String = ObjectSav<a href="https://www.jb51.cc/tag/eto/" target="_blank" class="keywords">eto</a>String & IIf(bytData(i) < 16,"0","") & Hex(bytData(i)) Next End Function '- ----------------------------------- ' <a href="https://www.jb51.cc/tag/hanshu/" target="_blank" class="keywords">函数</a>说明：从字符串中加载类对象 '- ----------------------------------- Function ObjectLoadFromString(strSource As String,KeyName As String) As Object Dim i As Long,nLen As Long Dim objBag As New <a href="https://www.jb51.cc/tag/propertybag/" target="_blank" class="keywords">propertybag</a> Dim bytData() As Byte On Error Resume Next nLen = Len(strSource) If nLen = 0 Or Len(KeyName) = 0 Then Exit Function ReDim bytData(nLen / 2 - 1) For i = 0 To UBound(bytData) bytData(i) = Val("&H" & Mid(strSource,i * 2 + 1,2)) Next objBag.Contents = bytData Set ObjectLoadFromString = objBag.ReadProperty(KeyName) End Function

测试代码如下：

'测试<a href="https://www.jb51.cc/tag/daima/" target="_blank" class="keywords">代码</a>如下： Sub Main() Dim rstTemp As Object Dim strStream As String '创建<a href="https://www.jb51.cc/tag/yige/" target="_blank" class="keywords">一个</a>临时ADO记录集对象 Set rstTemp = CreateObject("ADODB.Recordset") rstTemp.Fields.Append "姓名",adBSTR,4 '设置临时记录集字段 rstTemp.Fields.Append "性别",1 rstTemp.Open '打开记录集 rstTemp.AddNew Array("姓名","性别"),Array("张三","男") '<a href="https://www.jb51.cc/tag/tianjiajilu/" target="_blank" class="keywords">添加记录</a> '将记录集对象序列化为字符串 strStream = ObjectSav<a href="https://www.jb51.cc/tag/eto/" target="_blank" class="keywords">eto</a>String(rstTemp,"rstTemp") '<a href="https://www.jb51.cc/tag/guanbi/" target="_blank" class="keywords">关闭</a>并销毁ADO记录集对象 rstTemp.Close Set rstTemp = <a href="https://www.jb51.cc/tag/nothing/" target="_blank" class="keywords">nothing</a> '从字符串中加载记录集对象 Set rstTemp = ObjectLoadFromString(strStream,"rstTemp") Debug.Print rstTemp.Fields(0).Value '<a href="https://www.jb51.cc/tag/xianshi/" target="_blank" class="keywords">显示</a>结果 '<a href="https://www.jb51.cc/tag/guanbi/" target="_blank" class="keywords">关闭</a>并销毁ADO记录集对象 rstTemp.Close Set rstTemp = <a href="https://www.jb51.cc/tag/nothing/" target="_blank" class="keywords">nothing</a> End Sub