捕获从ASP.NET生成的HTML

时间:2008-12-22 15:18:11

标签: asp.net html logging asp.net-2.0 render

如何最好地捕获aspx页面呈现的HTML(在我的实例中,用于记录)?

我不想使用Response.Write回写页面,因为它会弄乱我的网站布局。

使用Response.OutputStream或Response.Output的流导致ArgumentException({System.ArgumentException:Stream无法读取。)

3 个答案:

答案 0 :(得分:25)

好问题,我必须尝试一下,看看我是否可以创建一个HttpModule来完成你所描述的内容。

我没有尝试从响应流中读取任何运气,但使用ResponseFilter为我提供了捕获内容的方法。

以下代码似乎工作得很好,我想也许你可以使用代码作为基础。但请记住,这只是我快速拼凑的东西,它没有经过任何方式的测试。因此,如果没有适当的审查/测试等,请不要在任何生产环境中使用它。尽管如此,请随意评论;)

public class ResponseLoggerModule : IHttpModule
{
    private class ResponseCaptureStream : Stream
    {
        private readonly Stream _streamToCapture;
        private readonly Encoding _responseEncoding;

        private string _streamContent;
        public string StreamContent
        {
            get { return _streamContent; }
            private set
            {
                _streamContent = value;
            }
        }

        public ResponseCaptureStream(Stream streamToCapture, Encoding responseEncoding)
        {
            _responseEncoding = responseEncoding;
            _streamToCapture = streamToCapture;

        }

        public override bool CanRead
        {
            get { return _streamToCapture.CanRead; }
        }

        public override bool CanSeek
        {
            get { return _streamToCapture.CanSeek; }
        }

        public override bool CanWrite
        {
            get { return _streamToCapture.CanWrite; }
        }

        public override void Flush()
        {
            _streamToCapture.Flush();
        }

        public override long Length
        {
            get { return _streamToCapture.Length; }
        }

        public override long Position
        {
            get
            {
                return _streamToCapture.Position;
            }
            set
            {
                _streamToCapture.Position = value;
            }
        }

        public override int Read(byte[] buffer, int offset, int count)
        {
            return _streamToCapture.Read(buffer, offset, count);
        }

        public override long Seek(long offset, SeekOrigin origin)
        {
            return _streamToCapture.Seek(offset, origin);
        }

        public override void SetLength(long value)
        {
            _streamToCapture.SetLength(value);
        }

        public override void Write(byte[] buffer, int offset, int count)
        {
            _streamContent += _responseEncoding.GetString(buffer);
            _streamToCapture.Write(buffer, offset, count);
        }

        public override void Close()
        {
            _streamToCapture.Close();
            base.Close();
        }
    }

    #region IHttpModule Members

    private HttpApplication _context;
    public void Dispose()
    {

    }

    public void Init(HttpApplication context)
    {
        _context = context;

        context.PreRequestHandlerExecute += new EventHandler(context_PreRequestHandlerExecute);
        context.PreSendRequestContent += new EventHandler(context_PreSendRequestContent);
    }

    void context_PreRequestHandlerExecute(object sender, EventArgs e)
    {
        _context.Response.Filter = new ResponseCaptureStream(_context.Response.Filter, _context.Response.ContentEncoding);
    }

    void context_PreSendRequestContent(object sender, EventArgs e)
    {
        ResponseCaptureStream filter = _context.Response.Filter as ResponseCaptureStream;

        if (filter != null)
        {
            string responseText = filter.StreamContent;

            // Logging logic here
        }
    }

    #endregion
}

答案 1 :(得分:4)

许多负载测试人员将允许您记录生成的HTTP响应,但请记住,那些可能是一些非常大的日志文件。

编辑:Response.Filter根据Tom Jelen的代码旨在提供这种疏忽,而Response.Outputstream则无法读取。

编辑2:对于页面而不是HTTPModule

public class ObserverStream : Stream
{
  private byte[] buffer = null;
  private Stream observed = null;

  public ObserverStream (Stream s)
  {
    this.observed = s;
  }

  /* important method to extend #1 : capturing the data */
  public override void Write(byte[] buffer, int offset, int count)
  {
    this.observed.Write(buffer, offset, count);
    this.buffer = buffer; //captured!
  }

  /* important method to extend #2 : doing something with the data */
  public override void Close()
  {
    //this.buffer available for logging here!
    this.observed.Close();
  }

  /* override all the other Stream methods/props with this.observed.method() */

  //...

}

并在你的Page_Load中(或在你的回复被写入之前)

Response.Filter = new ObserverStream(Response.Filter);

答案 2 :(得分:1)

向您自己的服务器发出服务器端XMLHTTP请求的一种方法。抓取结果并将其保存到文件或数据库中。

或者,您可以在客户端上使用AJAX,获取结果,然后将其POST回服务器。