捕获从ASP.NET生成的HTML

Question

如何最好地捕获由aspx页面呈现的HTML(在我的实例中,用于日志记录)？

我不想使用Response.Write回写页面,因为它弄乱了我的网站布局.

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

Answer 1

好问题,我不得不尝试,看看我是否可以创建一个HTTP模块做你所描述的.

我没有任何运气试图从responsestream阅读,但使用ResponseFilter给了我一个方式捕捉的内容.

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,请随意发表评论;)

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
}