下载（打开）PDF文件 代码

网上的代码很多，但现在大多数都是Framework 3.5的啦，对于2.0，2.5有的方法不是很兼容，花了半个小时才找到一个合适，现在记录如下：

注意：不适合网络路径，只适合本地文件， 网络路径请参考我另一篇Blog

public void DownloadFile(string strFileNamePath)
    {
        long chunkSize = 102400;
        byte[] buffer = new byte[chunkSize];
        //long dataToRead=0;
        FileStream stream = null;
        try
        {
            FileInfo info = new FileInfo(strFileNamePath);
            Response.Clear();
            stream = new FileStream(strFileNamePath, FileMode.Open, FileAccess.Read, FileShare.Read);
            Response.Clear();
            Response.AddHeader("Content-Length", stream.Length.ToString());
            Response.ContentType = "application/pdf";
            long fileLength = stream.Length;
            int size = 10240;//10K一--分块下载，10K为1块
            byte[] readData = new byte[size];
            if (size > fileLength)
                size = Convert.ToInt32(fileLength);
            long fPos = 0;
            bool isEnd = false;
            while (!isEnd)
            {
                if ((fPos + size) >= fileLength)
                {
                    size = Convert.ToInt32(fileLength - fPos);
                    isEnd = true;
                }
                readData = new byte[size];
                stream.Position = fPos;
                stream.Read(readData, 0, size);
                Response.BinaryWrite(readData);
                Response.OutputStream.Flush();
                fPos += size;
            }
            stream.Close();
            Response.OutputStream.Close();
            Response.End();//非常重要，没有这句的话，页面的HTML代码将会保存到文件中
            Response.Close();
        }
        catch (Exception)
        {
            if (stream != null)
            {
                stream.Close();
                stream = null;
            }
        }

    }