c# - .Net XmlWriter - 意外的编码让我感到困惑

Question

环境是VS2008，.Net 3.5

以下C#代码(注意指定编码为UTF8)

XmlWriterSettings settings = new XmlWriterSettings ();
StringBuilder sb  = new StringBuilder();
settings.Encoding = System.Text.Encoding.UTF8;
settings.Indent   = false;
settings.NewLineChars = "\n";
settings.ConformanceLevel =  System.Xml.ConformanceLevel.Document;

XmlWriter writer = XmlWriter.Create (sb, settings);
{
   // Write XML data.
   writer.WriteStartElement ("CCHEADER");
   writer.WriteAttributeString ("ProtocolVersion", "1.0.0");
   writer.WriteAttributeString ("ServerCapabilities", "0x0000000F");
   writer.WriteEndElement ();
   writer.Flush ();
}

实际生成 XML(<省略，因为 SO 对它们很反感):

?xml version="1.0"encoding="utf-16"?
CCHEADER ProtocolVersion="1.0.0"ServerCapabilities="0x0000000F"/

为什么我在这里生成了错误的编码？我做错了什么？

Answer 1

我怀疑这是因为它正在写入一个本质上是 UTF-16 的 StringBuilder。解决此问题的另一种方法是创建一个派生自 StringWriter 的类，但它会覆盖 Encoding 属性。

我相信我在 MiscUtil 中有一个- 但无论如何写起来都很简单。像这样:

public sealed class StringWriterWithEncoding : StringWriter
{
    private readonly Encoding encoding;

    public StringWriterWithEncoding (Encoding encoding)
    {
        this.encoding = encoding;
    }

    public override Encoding Encoding
    {
        get { return encoding; }
    }
}