获得“我»¿”在sitemap.xml的年初通过MVC网站地图提供商

Question

public class HomeController : Controller 
{ 
    public ActionResult SitemapXML() 
    { 
     return new XmlSiteMapResult(); 
    } 
} 

如何生成编码UTF-8无地图BOM？

Answer 1

创建一个类来覆盖XmlSiteMapResult的默认行为，因此它排除了BOM。

public class MyXmlSiteMapResult : XmlSiteMapResult 
{ 

    /// <summary> 
    /// Maximal number of links per sitemap file. 
    /// </summary> 
    /// <remarks> 
    /// This number should be 50000 in theory, see http://www.sitemaps.org/protocol.php#sitemapIndex_sitemap. 
    /// Since sitemap files can be maximal 10MB per file and calculating the total sitemap size would degrade performance, 
    /// an average cap of 35000 has been chosen. 
    /// </remarks> 
    private const int MaxNumberOfLinksPerFile = 35000; 

    protected override void ExecuteSitemapIndexResult(ControllerContext context, IEnumerable<SiteMapNode> flattenedHierarchy, long flattenedHierarchyCount) 
    { 
     // Count the number of pages 
     double numPages = Math.Ceiling((double)flattenedHierarchyCount/MaxNumberOfLinksPerFile); 

     // Output content type 
     context.HttpContext.Response.ContentType = "text/xml"; 

     // Generate sitemap sitemapindex 
     var sitemapIndex = new XElement(Ns + "sitemapindex"); 
     sitemapIndex.Add(GenerateSiteMapIndexElements(Convert.ToInt32(numPages), Url, SiteMapUrlTemplate).ToArray()); 

     // Generate sitemap 
     var xmlSiteMap = new XDocument(
      new XDeclaration("1.0", "utf-8", "true"), 
      sitemapIndex); 

     // Specify to emit XML with no BOM 
     var settings = new XmlWriterSettings(); 
     settings.Encoding = new System.Text.UTF8Encoding(false); 

     // Write XML 
     using (Stream outputStream = RetrieveOutputStream(context)) 
     { 
      using (var writer = XmlWriter.Create(outputStream, settings)) 
      { 
       xmlSiteMap.WriteTo(writer); 
      } 
      outputStream.Flush(); 
     } 
    } 

    protected override void ExecuteSitemapResult(ControllerContext context, IEnumerable<SiteMapNode> flattenedHierarchy, long flattenedHierarchyCount, int page) 
    { 

     // Output content type 
     context.HttpContext.Response.ContentType = "text/xml"; 

     // Generate URL set 
     var urlSet = new XElement(Ns + "urlset"); 
     urlSet.Add(GenerateUrlElements(
      flattenedHierarchy.Skip((page - 1)* MaxNumberOfLinksPerFile) 
       .Take(MaxNumberOfLinksPerFile), Url).ToArray()); 

     // Generate sitemap 
     var xmlSiteMap = new XDocument(
      new XDeclaration("1.0", "utf-8", "true"), 
      urlSet); 

     // Specify to emit XML with no BOM 
     var settings = new XmlWriterSettings(); 
     settings.Encoding = new System.Text.UTF8Encoding(false); 

     // Write XML 
     using (Stream outputStream = RetrieveOutputStream(context)) 
     { 
      using (var writer = XmlWriter.Create(outputStream, settings)) 
      { 
       xmlSiteMap.WriteTo(writer); 
      } 
      outputStream.Flush(); 
     } 
    } 
} 

然后返回您的自定义类。

public class HomeController : Controller 
{ 
    public ActionResult SitemapXML() 
    { 
     return new MyXmlSiteMapResult(); 
    } 
} 

注：这个例子假设你正在使用MvcSiteMapProvider的V3，因为在V4中，XmlSiteMapResult类不再有默认的构造函数（在第4版，您必须使用XmlSiteMapResultFactory获得XmlSiteMapResult的一个实例，这样您还需要重写XmlSiteMapResultFactory以返回您的自定义类的实例）。

参考：How can I remove the BOM from XmlTextWriter using C#?