Question

如何在XElement中获取DataSet的Diffgram？（或XDocument）

我发现了如何在字符串中获取Diffgram：

        // DataSet to Diffgram in a string:
        StringBuilder sb = new StringBuilder();
        XmlWriterSettings settings = new XmlWriterSettings { Indent = true, Encoding = Encoding.UTF8 };
        using (XmlWriter xw = XmlWriter.Create(sb, settings))
        {
            ds.WriteXml(xw, XmlWriteMode.WriteSchema);//XmlWriteMode.DiffGram
        }
        string str = sb.ToString();

但是首先将一个diffgram的xml输出到一个字符串然后再将它解析为一个XElement似乎很浪费。所以我试图找出如何填写此代码中缺少的链接，该链接应该将diff的xml转换为Xml变量而无需转换：

        // I have a DataSet filled with some data
        DataSet ds = new DataSet();
        ds.Tables.Add(ScanData);

        // I need the diffgram of the DataSet in an XElement
        XElement xe = null;
        XmlReader xr = xe.CreateReader();

        // I could live with output to XDocument, and extract the XElement later
        XDocument xd = new XDocument();
        XmlReader xrd = xd.CreateReader();

        // Q: How do I construct a stream that connects an XmlReader to ds.WriteXml()?
        Stream stream =  ...???... ;

        // This method creates the DiffGram output format to a stream
        ds.WriteXml(stream, XmlWriteMode.WriteSchema);//diffgram output

我希望找到我的代码问题的答案，甚至可以了解流/读者/作者如何真正起作用。

Answer 1

您需要一个编写器，而不是读者，从DataSet写入XDocument：

XDocument xd = new XDocument();
using (var writer = xd.CreateWriter())
{
    ds.WriteXml(writer, XmlWriteMode.WriteSchema); // XmlWriteMode.DiffGram
}

C＃Diffgram to XElement，Reader / Writer混淆

1 个答案: