gzipStream 异步的问题

Question

本人最近在写一个软件里面用到了GZIPSTREAM压缩数据,为了可以响应用户界面的操作我使用了异步来操作.以下是具体代码请高手过目问题也在代码下给出
private Boolean compressDateByFile(String inFilePath,String outFilePath)
        {
            int bufferSize = 2048;
            this.isComplete = false;
            Boolean compressSuccess = false;//标记异步压缩完成
            Byte[] buffer = null;
            try 
        {
                buffer = new Byte[bufferSize];
                FileStream inFS = new FileStream(inFilePath, FileMode.Open, FileAccess.Read, FileShare.Read, bufferSize, true);
                this.totalSize=inFS.Length;
                FileStream outFS = new FileStream(outFilePath, FileMode.Create, FileAccess.Write, FileShare.Write, bufferSize, true);
                GZipStream zipStream = new GZipStream(outFS, CompressionMode.Compress);
                AsyncCallback readCallback = null;
                AsyncCallback writeCallback = null;
                writeCallback = delegate(IAsyncResult asyncResult)
                {
                    zipStream.EndWrite(asyncResult);
                    int newSize=int.Parse(asyncResult.AsyncState.ToString());
                    if (newSize != 0)
                    {
                        this.curSize += newSize;
                        this.percent = calcPercent(this.curSize, this.totalSize);
                    }
                    else
                    {
                        this.isComplete = true;
                        zipStream.Close();
                    }
                };
                readCallback = delegate(IAsyncResult asyncResult)
                {
                    int readByteCount = inFS.EndRead(asyncResult);
                    if (readByteCount > 0)
                    {
                        //没有到结尾                        
                        inFS.BeginRead(buffer, 0, buffer.Length, readCallback, null);
                        
                    }
                    else
                    {
                        //到结尾了
                        inFS.Close();
                    }
                    zipStream.BeginWrite(buffer, 0, buffer.Length, writeCallback, readByteCount);
                };
                IAsyncResult async=inFS.BeginRead(buffer, 0, buffer.Length, readCallback, null);
                compressSuccess = true;
            }
        catch (Exception exc)
        {
                MessageBox.Show(exc.Message);
        }
            return compressSuccess;
        }
我的想法就是异步读异步写, 异步读取到BUFFER缓存然后异步写入压缩流中.然后在读.再写.....这样直到读完为止..可是出现异常了说只能执行一个异步...不知道哪里出问题了,请高手们帮帮我吧或者给我一个更好的解决方法,我在这里谢谢各位了!