XmlReader 读取器读取内存流 MemoryStream 的注意事项

MemoryStream对象提供了无需进行IO就可以创建Stream的方法，XmlTextWriter和XmlReader提供快速书写和读取XML内容的方法，结合MemoryStream，就可以直接在内存中构造XmlTextWriter，并用XmlReader进行读取。

使用MemoryStream和XmlTextWriter进行书写XML,需要注意两点：XmlTextWriter.Flush操作和重设MemoryStream.Position=0。

<%@PageLanguage="C#"%>

<%@ImportNamespace="System.Xml"%>

<%@ImportNamespace="System.IO"%>

<!DOCTYPEhtmlPUBLIC"-//W3C//DTDXHTML1.0Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<scriptrunat="server">

protectedvoidButton1_Click(objectsender,EventArgse)

{

Response.Clear();

Response.ContentType="text/xml";

MemoryStreammsXml=newMemoryStream();

XmlTextWriterxmlWriter=newXmlTextWriter(msXml,Encoding.UTF8);

xmlWriter.WriteStartElement("rss");

xmlWriter.WriteAttributeString("version","2.0");

xmlWriter.WriteStartElement("channel");

xmlWriter.WriteElementString("title","【孟宪会之精彩世界】");

xmlWriter.WriteElementString("link","http://dotnet.aspx.cc/Rss.aspx");

xmlWriter.WriteElementString("description","NET开发技术。");

xmlWriter.WriteElementString("language","zh-CN");

xmlWriter.WriteElementString("managingEditor","amxh[AT]21cn.com");

xmlWriter.WriteStartElement("image");

xmlWriter.WriteElementString("title","【孟宪会之精彩世界】");

xmlWriter.WriteElementString("width","144");

xmlWriter.WriteElementString("height","35");

xmlWriter.WriteElementString("link","http://dotnet.aspx.cc/");

xmlWriter.WriteElementString("url","http://dotnet.aspx.cc/Images/LogoRss.gif");

xmlWriter.WriteEndElement();

//循环读出数据库内容列表，忽略

//while(objReader.Read())

//{

//xmlWriter.WriteStartElement("item");

//xmlWriter.WriteElementString("title",objReader.GetString(0));

//xmlWriter.WriteElementString("description",objReader.GetString(1));

//xmlWriter.WriteElementString("link","http://dotnet.aspx.cc/article/a933b187-06c3-4263-9eec-414a54d9c815/read.aspx");

//xmlWriter.WriteElementString("pubDate",objReader.GetDateTime(3).ToString("G"));

//xmlWriter.WriteEndElement();

//}

//objReader.Close();

xmlWriter.WriteStartElement("item");

xmlWriter.WriteElementString("title","ASP.NET2.0中直接将Access数据库导入到Excel文件中");

xmlWriter.WriteElementString("description","ASP.NET2.0中直接将Access数据库导入到Excel文件中");

xmlWriter.WriteElementString("link","http://dotnet.aspx.cc/article/a933b187-06c3-4263-9eec-414a54d9c815/read.aspx");

xmlWriter.WriteElementString("pubDate","Sat,02Dec200609:39:58GMT");

xmlWriter.WriteEndElement();

xmlWriter.Flush();//确保书写器更新到Stream中；

msXml.Position=0;//重置流的位置，以便我们可以从头读取

XmlReaderxmlReader=XmlReader.Create(msXml);

while(xmlReader.Read())

{

if(xmlReader.Name=="rss")

{

Response.Write(xmlReader.ReadOuterXml());

}

Response.End();

msXml.Close();

xmlWriter.Close();

xmlReader.Close();

}

</script>

<htmlxmlns="http://www.w3.org/1999/xhtml">

<headrunat="server">

<title>XmlReader读取器读取内存流MemoryStream的注意事项</title>

</head>

<body>

<formid="form1"runat="server">

<asp:ButtonID="Button1"runat="server"OnClick="Button1_Click"Text="读取数据"/>

</form>

</body>

</html>

VB.NET

ProtectedSubButton1_Click(ByValsenderAsObject,ByValeAsEventArgs)

Response.Clear

Response.ContentType="text/xml"

DimmsXmlAsMemoryStream=NewMemoryStream

DimxmlWriterAsXmlTextWriter=NewXmlTextWriter(msXml,Encoding.UTF8)

xmlWriter.WriteStartElement("rss")

xmlWriter.WriteAttributeString("version","2.0")

xmlWriter.WriteStartElement("channel")

xmlWriter.WriteElementString("title","【孟宪会之精彩世界】")

xmlWriter.WriteElementString("link","http://dotnet.aspx.cc/Rss.aspx")

xmlWriter.WriteElementString("description","NET开发技术。")

xmlWriter.WriteElementString("language","zh-CN")

xmlWriter.WriteElementString("managingEditor","amxh[AT]21cn.com")

xmlWriter.WriteStartElement("image")

xmlWriter.WriteElementString("title","【孟宪会之精彩世界】")

xmlWriter.WriteElementString("width","144")

xmlWriter.WriteElementString("height","35")

xmlWriter.WriteElementString("link","http://dotnet.aspx.cc/")

xmlWriter.WriteElementString("url","http://dotnet.aspx.cc/Images/LogoRss.gif")

xmlWriter.WriteEndElement

xmlWriter.WriteStartElement("item")

xmlWriter.WriteElementString("title","ASP.NET2.0中直接将Access数据库导入到Excel文件中")

xmlWriter.WriteElementString("description","ASP.NET2.0中直接将Access数据库导入到Excel文件中")

xmlWriter.WriteElementString("link","http://dotnet.aspx.cc/article/a933b187-06c3-4263-9eec-414a54d9c815/read.aspx")

xmlWriter.WriteElementString("pubDate","Sat,02Dec200609:39:58GMT")

xmlWriter.WriteEndElement

xmlWriter.Flush

msXml.Position=0

DimxmlReaderAsXmlReader=XmlReader.Create(msXml)

WhilexmlReader.Read

IfxmlReader.Name="rss"Then

Response.Write(xmlReader.ReadOuterXml)

EndIf

EndWhile

Response.End

msXml.Close

xmlWriter.Close

xmlReader.Close

EndSub