如何在 .Net 2.0/C# 中将 StreamReader 转换为 XMLReader 对象
题
这是我今天一直在思考的一个简单问题。
我正在尝试将 .Net 数据集转换为 XML 流,使用内存中的 xsl 文件对其进行转换,然后将结果输出到新的 XML 文件。
这是当前的解决方案:
string transformXML = @"pathToXslDocument";
XmlDocument originalXml = new XmlDocument();
XmlDocument transformedXml = new XmlDocument();
XslCompiledTransform transformer = new XslCompiledTransform();
DataSet ds = new DataSet();
string filepath;
originalXml.LoadXml(ds.GetXml()); //data loaded prior
StringBuilder sb = new StringBuilder();
XmlWriter writer = XmlWriter.Create(sb);
transformer.Load(transformXML);
transformer.Transform(originalXml, writer); //no need to select the node
transformedXml.LoadXml(sb.ToString());
transformedXml.Save(filepath);
writer.Close();
这是原始代码:
BufferedStream stream = new BufferedStream(new MemoryStream());
DataSet ds = new DataSet();
da.Fill(ds);
ds.WriteXml(stream);
StreamReader sr = new StreamReader(stream, true);
stream.Position = 0; //I'm not certain if this is necessary, but for the StreamReader to read the text the position must be reset.
XmlReader reader = XmlReader.Create(sr, null); //Problem is created here, the XmlReader is created with none of the data from the StreamReader
XslCompiledTransform transformer = new XslCompiledTransform();
transformer.Load(@"<path to xsl file>");
transformer.Transform(reader, null, writer); //Exception is thrown here, though the problem originates from the XmlReader.Create(sr, null)
由于某种原因,在 Transformer.Transform 方法中,读取器没有根节点,实际上读取器没有从 StreamReader 读取任何内容。
我的问题是这段代码有什么问题?其次,是否有更好的方法将数据集转换/转换/存储为 XML?
编辑:这两个答案都有帮助,而且从技术上讲,aku 的答案更接近。然而,在尝试了这两种解决方案之后,我倾向于一种更类似于 Longhorn 的解决方案。
解决方案
我不确定,但在将流传递给 XmlReader 之前,您似乎没有重置流中的位置。在尝试读取流之前,请尝试先在流的开头进行查找。此外,在向流写入一些数据后,可能需要关闭\刷新流。
编辑:
刚刚尝试了以下代码,它运行得很好:
BufferedStream stream = new BufferedStream(new MemoryStream());
stream.Write(Encoding.ASCII.GetBytes("<xml>foo</xml>"), 0, "<xml>foo</xml>".Length);
stream.Seek(0, SeekOrigin.Begin);
StreamReader sr = new StreamReader(stream);
XmlReader reader = XmlReader.Create(sr);
while (reader.Read())
{
Console.WriteLine(reader.Value);
}
stream.Close();
其他提示
您必须选择根节点。这不使用数据集,但我每天都使用这个函数,而且效果很好。
System.Xml.XmlDocument orgDoc = new System.Xml.XmlDocument();
orgDoc.LoadXml(orgXML);
// MUST SELECT THE ROOT NODE
XmlNode transNode = orgDoc.SelectSingleNode("/");
System.Text.StringBuilder sb = new System.Text.StringBuilder();
XmlWriter writer = XmlWriter.Create(sb);
System.IO.StringReader stream = new System.IO.StringReader(transformXML);
XmlReader reader = XmlReader.Create(stream);
System.Xml.Xsl.XslCompiledTransform trans = new System.Xml.Xsl.XslCompiledTransform();
trans.Load(reader);
trans.Transform(transNode, writer);
XmlDocument doc = new XmlDocument();
doc.LoadXml(sb.ToString());
return doc;
请查看并使用..
using (MemoryStream memStream = new MemoryStream())
{
memStream.Write(Encoding.UTF8.GetBytes(xmlBody), 0, xmlBody.Length);
memStream.Seek(0, SeekOrigin.Begin);
using (StreamReader reader = new StreamReader(memStream))
{
// xml reader setting.
XmlReaderSettings xmlReaderSettings = new XmlReaderSettings()
{
IgnoreComments = true,
IgnoreWhitespace = true,
};
// xml reader create.
using (XmlReader xmlReader = XmlReader.Create(reader, xmlReaderSettings))
{
XmlSerializer xmlSerializer = new XmlSerializer(typeof(LoginInfo));
myObject = (LoginInfo)xmlSerializer.Deserialize(xmlReader);
}
}
}
不隶属于 StackOverflow