怎么往文件里写XML去掉BOM啊？

我用下面这种方法，但是输出的XML有问题啊？

private static string GetXmlPhotoTemplate()

{

string strResult = string.Empty;

string resourceName = string.Format("{0}.{1}", MethodBase.GetCurrentMethod().DeclaringType.Namespace, "XmlPhotoTemplate.xml");

using (Stream stream = Assembly.GetExecutingAssembly().GetManifestResourceStream(resourceName))

{

if (stream != null)

{

byte[] buffer = new byte[stream.Length];

stream.Read(buffer, 0, buffer.Length);

strResult = Encoding.GetEncoding("utf-16").GetString(buffer);

}

}

return strResult;

}

static void Main(string[] args)

{

FileStream fs=new FileStream(@"c:\XmlPhotoTemplate.xml",FileMode.Truncate,FileAccess.ReadWrite);

XmlWriterSettings settings = new XmlWriterSettings();

settings.Indent = true;

settings.ConformanceLevel = ConformanceLevel.Auto;

XmlWriter writer = XmlWriter.Create(fs, settings);

writer.WriteString(GetXmlPhotoTemplate());

writer.Close();

fs.Close();

Console.ReadLine();

}

怎么输出的XML有问题啊

<?xml version="1.0" encoding="utf-16"?>

<Media name="%filename%" propertyID="%eid%">

<Provider id="6"/>

<Subcategory id="%subcategoryid%"/>

<Rooms>

<Room id=""/>

<Room id=""/>

</Rooms>

<Activities>

<Activity type="Acquisition" application="SCORE" time="%timestamp%"/>

</Activities>

</Media>