数据集->XML 文档 - 将数据集加载到 XML 文档中 - C#.Net [英] Dataset -> XML Document - Load DataSet into an XML Document - C#.Net

问题描述

我正在尝试以 xml 格式读取数据集并将其加载到 XML 文档中.

I'm trying to read a dataset as xml and load it into an XML Document.

XmlDocument contractHistoryXMLSchemaDoc = new XmlDocument();

using (MemoryStream ms = new MemoryStream())
{
   //XmlWriterSettings xmlWSettings = new XmlWriterSettings();

   //xmlWSettings.ConformanceLevel = ConformanceLevel.Auto;
   using (XmlWriter xmlW = XmlWriter.Create(ms))
   {
      xmlW.WriteStartDocument();
      dsContract.WriteXmlSchema(xmlW);
      xmlW.WriteEndDocument();
      xmlW.Close();
      using (XmlReader xmlR = XmlReader.Create(ms))
      {
         contractHistoryXMLSchemaDoc.Load(xmlR);
      }
   }
}

但我收到错误消息 - 缺少根元素".

But I'm getting the error - "Root Element Missing".

有什么想法吗?

更新

当我执行 xmlR.ReadInnerXML() 时，它是空的.有谁知道为什么?

When i do xmlR.ReadInnerXML() it is empty. Does anyone know why?

NLV

推荐答案

关于原代码的几点说明:

A few things about the original code:

• 您不需要调用写入开始和结束文档方法:DataSet.WriteXmlSchema 生成完整、格式良好的 xsd.
• 写入架构后，流位于其末尾，因此当您调用 XmlDocument.Load 时，XmlReader 没有任何内容可供读取.

• You don't need to call the write start and end document methods: DataSet.WriteXmlSchema produces a complete, well-formed xsd.
• After writing the schema, the stream is positioned at its end, so there's nothing for the XmlReader to read when you call XmlDocument.Load.

所以主要是你需要使用Seek重置MemoryStream的位置.您还可以稍微简化整个方法:您不需要 XmlReader 或 writer.以下对我有用:

So the main thing is that you need to reset the position of the MemoryStream using Seek. You can also simplify the whole method quite a bit: you don't need the XmlReader or writer. The following works for me:

XmlDocument xd = new XmlDocument();
using(MemoryStream ms = new MemoryStream())  
{
    dsContract.WriteXmlSchema(ms);

    // Reset the position to the start of the stream
    ms.Seek(0, SeekOrigin.Begin);
    xd.Load(ms);
}

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