asp.net mvc:如何将非www重定向到www,反之亦然

protected void Application_Start()
{
    // 启用URL重定向规则
    RouteConfig.RegisterRoutes(RouteTable.Routes);
    RedirectNonWwwUrls();
}

private void RedirectNonWwwUrls()
{
    // 获取当前请求的URL
    var requestUrl = HttpContext.Current.Request.Url;
    
    // 检查是否为非www开头的URL
    if (!requestUrl.Host.StartsWith("www."))
    {
        // 构建重定向URL
        var redirectUrl = new UriBuilder(requestUrl)
        {
            Host = "www." + requestUrl.Host
        }.ToString();
        
        // 执行重定向
        HttpContext.Current.Response.RedirectPermanent(redirectUrl);
    }
}

// 检查是否为www开头的URL
if (requestUrl.Host.StartsWith("www."))
{
    // 构建重定向URL
    var redirectUrl = new UriBuilder(requestUrl)
    {
        Host = requestUrl.Host.Replace("www.", "")
    }.ToString();
    
    // 执行重定向
    HttpContext.Current.Response.RedirectPermanent(redirectUrl);
}

<system.webServer>
  <rewrite>
    <rules>
      <rule name="Redirect to www" stopProcessing="true">
        <match url="(.*)" />
        <conditions>
          <add input="{HTTP_HOST}" pattern="^(?!www\.)(.*)$" />
        </conditions>
        <action type="Redirect" url="http://www.{C:0}/{R:1}" redirectType="Permanent" />
      </rule>
    </rules>
  </rewrite>
</system.webServer>