在CommonFilter 增加GZIP压缩总是不完整

[cnw168]

我重写了Response.Filter，我想在CommonFilter 中进行GZIP压缩。就是第一次打开网页时进行压缩并保存成文件，下次直接读取文件加上context.Response.AppendHeader("Content-Encoding", "gzip");就可以了。

但用如下代码，压缩后的网页总是不完整，不管把Close();放到什么位置一样不完整。使用GZipOutputStream也是一样不完整。如果要是写到外面不保存成文件一切正常。如：

//		context.Response.Filter = new GZipStream(context.Response.Filter, CompressionMode.Compress);
//		context.Response.AppendHeader("Content-Encoding", "gzip");

    
context.Response.Filter = new CommonFilter(context.Response.Filter, stream);
public class CommonFilter : Stream  
    {  
        private readonly Stream _responseStream;  
        private readonly FileStream _cacheStream;  
        public override bool CanRead  
        {  
             get 
            {  
                 return false;  
             }  
        }  
         public override bool CanSeek  
         {  
             get 
           {  
                 return false;  
             }  
         }  
         public override bool CanWrite  
         {  
            get 
             {  
                 return _responseStream.CanWrite;  
             }  
         }  
        public override long Length  
        {  
             get 
             {  
                 throw new NotSupportedException();  
            }  
         }  
         public override long Position  
         {  
            get 
            {  
               throw new NotSupportedException();  
            }  
             set 
            {  
                 throw 
                    new NotSupportedException();  
             }  
         }  
         public CommonFilter(Stream responseStream, FileStream stream)  
         {  
             _responseStream = responseStream;  
             _cacheStream = stream;  
         }  
         public override long Seek(long offset, SeekOrigin origin)  
        {  
            throw new NotSupportedException();  
         }  
        public override void SetLength(long length)  
         {  
            throw new NotSupportedException();  
        }  
        public override int Read(byte[] buffer, int offset, int count)  
        {  
           throw new NotSupportedException();  
         }  

         public override void Flush()  
         {  
             _responseStream.Flush();  
            _cacheStream.Flush();  
         }  
         public override void Write(byte[] buffer, int offset, int count)  
         {
    using (MemoryStream msTemp = new MemoryStream(count))
    {
        using (GZipStream gz = new GZipStream(msTemp, CompressionMode.Compress, true))
        {
            gz.Write(buffer,offset, count);
            gz.Close();
            buffer = msTemp.ToArray();
	   count=(int)msTemp.Length;
        }
    }

             _cacheStream.Write(buffer, offset,count); 
             _responseStream.Write(buffer, offset,count);  
         }  
         public override void Close()  
         {  
            _responseStream.Close();  
             _cacheStream.Close();  
         }  
        protected override void Dispose(bool disposing)  
         {  
             if (disposing)  
             {  
                 _responseStream.Dispose();  
                 _cacheStream.Dispose();  
             }  
         }  
     }  

[cnw168]

问题就出在
using (MemoryStream msTemp = new MemoryStream(count))
{
using (GZipStream gz = new GZipStream(msTemp, CompressionMode.Compress, true))
{
gz.Write(buffer,offset, count);
gz.Close();
buffer = msTemp.ToArray();
count=(int)msTemp.Length;
}
}

怎么调都不行。

[cnw168]

问题就出在
using (MemoryStream msTemp = new MemoryStream(count))
{
using (GZipStream gz = new GZipStream(msTemp, CompressionMode.Compress, true))
{
gz.Write(buffer,offset, count);
gz.Close();
buffer = msTemp.ToArray();
count=(int)msTemp.Length;
}
}

怎么调都不行。

[jshi123]

试下把GZipStream gz改成类成员变量，不要每次写数据时都创建一个新的GZipStream

[cnw168]

怎么写可以说具体点吗

[jshi123]

把Write方法改成这样：
GZipStream _gz;
public override void Write(byte[] buffer, int offset, int count)
{
_gz.Write(buffer,offset, count);
}

[equwo]

非要这样吗，你可以换个思路试试。