通过httpmodule确定页面大小

我有一个实现流重写器的httpmodule。它派生自stream类。在我的httpmodule中,我有以下代码:

void app_PreRequestHandlerExecute(object sender, EventArgs e)
{
    HttpResponse response = HttpContext.Current.Response;
    response.Filter = new MyRewriterStream(response.Filter);
}

在stream类中,我有以下代码重写默认的write方法:

public override void Write(byte[] buffer, int offset, int count)
{
     string outStr;
     outStr = UTF8Encoding.UTF8.GetString(buffer, offset, count);
     //Do useful stuff and write back to the stream
}

你只需在第二个点取字符串的长度