.net 如何从WCF服务返回流?
我在玩protobuf网络和WCF。以下是我创建的代码:.net 如何从WCF服务返回流?,.net,wcf,stream,protobuf-net,.net,Wcf,Stream,Protobuf Net,我在玩protobuf网络和WCF。以下是我创建的代码: public class MobileServiceV2 { [WebGet(UriTemplate = "/some-data")] [Description("returns test data")] public Stream GetSomeData() { WebOperationContext.Current.OutgoingResponse.ContentType = "appl
public class MobileServiceV2
{
[WebGet(UriTemplate = "/some-data")]
[Description("returns test data")]
public Stream GetSomeData()
{
WebOperationContext.Current.OutgoingResponse.ContentType = "application/x-protobuf";
var ms = new MemoryStream();
ProtoBuf.Serializer.Serialize(ms, new MyResponse { SomeData = "Test data here" });
return ms;
}
}
[DataContract]
public class MyResponse
{
[DataMember(Order = 1)]
public string SomeData { get; set; }
}
当我查看Fiddler时,我可以看到正确的传出内容类型,所有内容看起来都很好,但我得到的是空的响应。IE提示下载文件,但该文件为空。序列化程序不工作吗?还是我做得不对
编辑:
我在方法中添加了以下代码,是的,它可以正确地序列化。我如何从WCF返回流时出错
using (var file = File.Create("C:\\test.bin"))
{
Serializer.Serialize(file, new MyResponse { SomeData = "Test data here" });
}
请往这边走
var ms = new MemoryStream();
using (var file = File.Create("C:\\test.bin"))
{
Serializer.Serialize(file, new MyResponse { SomeData = "Test data here" });
file.CopyTo(ms);
}
return ms;//stream
只需写一个MemoryStream,然后倒带它。在这种情况下,不要处理它:
var ms = new MemoryStream();
Serializer.Serialize(ms, obj);
ms.Position = 0;
return ms;
然而,这并不意味着它会在内存中缓冲。我可以试着想出一些巫毒来避免这种情况,但这将是非常复杂的。如果我正确理解这个问题,您正在尝试使用流式WCF绑定。在这种情况下,您可以尝试将数据拆分为块,这些块在客户端上以相同的方式分别序列化和反序列化。唯一需要注意的是接收端WCF提供的流实现——您需要自己包装它并管理读取。以下是我用来促进这一点的一个类:
public static class StreamingUtility
{
public static IEnumerable<T> FromStream<T>(this Stream value, Action<T> perItemCallback = null)
{
List<T> result = new List<T>();
StreamProxy sp = new StreamProxy(value);
try
{
while (sp.CanRead)
{
T v = ProtoBuf.Serializer.DeserializeWithLengthPrefix<T>((Stream)sp, ProtoBuf.PrefixStyle.Base128);
if (perItemCallback != null)
perItemCallback(v);
result.Add(v);
}
}
catch { }
return result;
}
public static StreamingContent<T> SingleToStream<T>(this T value)
{
return new StreamingContent<T>(new T[] { value });
}
public static StreamingContent<T> ToStream<T>(this IEnumerable<T> value)
{
return new StreamingContent<T>(value);
}
public class StreamingContent<T> : Stream
{
private bool _canRead = true;
private ManualResetEventSlim _dataIsReady = new ManualResetEventSlim(false);
private bool _noMoreAdditions = false;
private long _readingOffset = 0;
//private IFormatter _serializer = new BinaryFormatter(null, new StreamingContext(StreamingContextStates.CrossMachine));
private IEnumerable<T> _source = null;
private MemoryStream _stream = new MemoryStream();
public static StreamingContent<T> Clone(Stream origin)
{
return new StreamingContent<T>(origin);
}
private StreamingContent(Stream origin)
{
byte[] b = new byte[65536];
while (true)
{
int count = origin.Read(b, 0, b.Length);
if (count > 0)
{
_stream.Write(b, 0, count);
}
else
break;
}
_noMoreAdditions = true;
}
public StreamingContent(IEnumerable<T> source)
{
if (!s_initialized)
{
StreamingUtility.Initialize();
StreamingUtility.s_initialized = true;
}
_source = source.ToList();
if (source.Count() > 0)
{
new Thread(new ParameterizedThreadStart(obj =>
{
StreamingContent<T> _this = obj as StreamingContent<T>;
foreach (T item in _this._source)
{
lock (_this._stream)
{
if (_this._noMoreAdditions) break;
_stream.Seek(0, SeekOrigin.End);
ProtoBuf.Serializer.SerializeWithLengthPrefix<T>(_this._stream, item, ProtoBuf.PrefixStyle.Base128);
//_serializer.Serialize(_this._stream, item);
_dataIsReady.Set();
}
}
lock (_this._stream)
{
_this._noMoreAdditions = true;
_dataIsReady.Set();
}
})) { IsBackground = true }.Start(this);
}
else
{
_canRead = false;
}
}
public override bool CanRead
{
get { return _canRead; }
}
public override bool CanSeek
{
get { return false; }
}
public override bool CanWrite
{
get { return false; }
}
public override long Length
{
get
{
while (!_noMoreAdditions) Thread.Sleep(20);
return _stream.Length;
}
}
public override long Position
{
get
{
throw new Exception("This stream does not support getting the Position property.");
}
set
{
throw new Exception("This stream does not support setting the Position property.");
}
}
public override void Close()
{
lock (_stream)
{
_noMoreAdditions = true;
_stream.Close();
}
}
public override void Flush()
{
}
public override int Read(byte[] buffer, int offset, int count)
{
if (!CanRead) return 0;
bool wait = false;
lock (_stream)
{
wait = !_dataIsReady.IsSet && !_noMoreAdditions;
}
if (wait)
{
_dataIsReady.Wait();
}
lock (_stream)
{
if (!_noMoreAdditions)
_dataIsReady.Reset();
if (_stream.Length > _readingOffset)
{
_stream.Seek(_readingOffset, SeekOrigin.Begin);
int res = _stream.Read(buffer, 0, count);
if (_noMoreAdditions && count + _readingOffset >= _stream.Length)
_canRead = false;
_readingOffset += res;
return res;
}
}
return 0;
}
public override long Seek(long offset, SeekOrigin origin)
{
throw new Exception("This stream does not support seeking.");
}
public override void SetLength(long value)
{
throw new Exception("This stream does not support setting the Length.");
}
public override void Write(byte[] buffer, int offset, int count)
{
throw new Exception("This stream does not support writing.");
}
protected override void Dispose(bool disposing)
{
try
{
lock (_stream)
{
_noMoreAdditions = true;
_stream.Close();
}
}
catch { }
}
}
private class StreamProxy : Stream
{
private bool _canRead = true;
private bool _endOfMessage = false;
private Stream _internalStream;
private int _readPosition = 0;
private MemoryStream _storage = new MemoryStream();
private int _writePosition = 0;
public StreamProxy(Stream internalStream)
{
_internalStream = internalStream;
byte[] initialRequest = new byte[1000];
int length = _internalStream.Read(initialRequest, 0, 1000);
if (length != 0)
_storage.Write(initialRequest, 0, length);
else
_canRead = false;
_writePosition = length;
}
public override bool CanRead
{
get { return _canRead; }
}
public override bool CanSeek
{
get { return false; }
}
public override bool CanWrite
{
get { return false; }
}
public override long Length
{
get { throw new NotImplementedException(); }
}
public override long Position
{
get
{
return _readPosition;
}
set
{
throw new NotImplementedException();
}
}
public override void Flush()
{
}
public override int ReadByte()
{
byte[] res = new byte[1];
int g = Read(res, 0, 1);
return res[0];
}
public override int Read(byte[] buffer, int offset, int count)
{
int res = 0;
if (_readPosition + count > _writePosition)
{
/// add extra bytes to see if more data is available and we need to allow next read
int readSize = _readPosition + count - _writePosition;
if (readSize < 1024)
readSize = 1024;
byte[] read = new byte[readSize];
res = _internalStream.Read(read, 0, readSize);
if (res > 0)
{
_storage.Seek(_writePosition, SeekOrigin.Begin);
_writePosition += res;
_storage.Write(read, 0, res);
}
else if (res == 0)/// If the read returned 0, we're at the end
{
_endOfMessage = true;
}
if (res > 0 && res < readSize)
{
read = new byte[1024];
res = _internalStream.Read(read, 0, 1024);
if (res > 0)
{
_storage.Seek(_writePosition, SeekOrigin.Begin);
_writePosition += res;
_storage.Write(read, 0, res);
}
else if (res == 0)/// If the read returned 0, we're at the end
{
_endOfMessage = true;
}
}
}
_storage.Seek(_readPosition, SeekOrigin.Begin);
res = _storage.Read(buffer, offset, count);
_readPosition += res;
/// If end of message was reached and all the data was read from the
/// internal storage, mark CanRead as false
if (_readPosition >= _writePosition && _endOfMessage)
_canRead = false;
return res;
}
public override long Seek(long offset, SeekOrigin origin)
{
throw new NotImplementedException();
}
public override void SetLength(long value)
{
throw new NotImplementedException();
}
public override void Write(byte[] buffer, int offset, int count)
{
throw new NotImplementedException();
}
}
}
公共静态类StreamingUtility
{
公共静态IEnumerable FromStream(此流值,Action perItemCallback=null)
{
列表结果=新列表();
StreamProxy sp=新的StreamProxy(值);
尝试
{
while(sp.CanRead)
{
tV=ProtoBuf.Serializer.DeserializeWithLengthPrefix((Stream)sp,ProtoBuf.PrefixStyle.Base128);
if(perItemCallback!=null)
围手术期(v);
结果:添加(v);
}
}
捕获{}
返回结果;
}
公共静态流化内容SingleToStream(此T值)
{
返回新的StreamingContent(新的T[]{value});
}
公共静态流化内容到流(此IEnumerable值)
{
返回新的StreamingContent(值);
}
公共类StreamingContent:Stream
{
私有bool_canRead=true;
private ManualResetEventSlim\u dataIsReady=新的ManualResetEventSlim(假);
私有bool _noMoreAdditions=false;
专用长_readingOffset=0;
//私有IFormatter_serializer=新的二进制格式化程序(null,新的StreamingContext(streamingContextState.CrossMachine));
私有IEnumerable _source=null;
私有内存流_stream=新内存流();
公共静态流化内容克隆(流源)
{
返回新的StreamingContent(源文件);
}
私有StreamingContent(流源)
{
字节[]b=新字节[65536];
while(true)
{
int count=origin.Read(b,0,b.Length);
如果(计数>0)
{
_stream.Write(b,0,count);
}
其他的
打破
}
_NOMOREAD加法=真;
}
公共流化内容(IEnumerable源)
{
如果(!s_已初始化)
{
StreamingUtility.Initialize();
StreamingUtility.s_initialized=true;
}
_source=source.ToList();
if(source.Count()>0)
{
新线程(新参数化线程启动(obj=>
{
StreamingContent _this=obj作为StreamingContent;
foreach(T项在_this._source中)
{
锁定(_this._stream)
{
如果(_this._noMoreAdditions)中断;
_stream.Seek(0,SeekOrigin.End);
ProtoBuf.Serializer.SerializeWithLengthPrefix(_this._stream,item,ProtoBuf.PrefixStyle.Base128);
//_serializer.Serialize(_this._stream,item);
_dataIsReady.Set();
}
}
锁定(_this._stream)
{
_这是.\u noMoreAdditions=true;
_dataIsReady.Set();
}
})){IsBackground=true}.Start(this);
}
其他的
{
_canRead=false;
}
}
公共覆盖布尔可读取
{
获取{return\u canRead;}
}
公共覆盖布尔搜索
{
获取{return false;}
}
公共覆盖布尔可写
{
获取{return false;}
}
公共覆盖长长度
{
得到
{
while(!_nomore)线程。Sleep(20);
返回流长度;
}
}
公众优先多头仓位
{
得到
{
抛出新异常(“此流不支持获取Position属性”);
}
设置
{
抛出新异常(“此流不支持设置Position属性”);
}
}
公共覆盖无效关闭()
{
锁(_流)
{
_NOMOREAD加法=真;
_stream.Close();
}
}
公共覆盖无效刷新()
{
}
公共重写整型读取(字节[]缓冲区、整型偏移量、整型计数)
{
如果(!CanRead)返回0;
bool wait=false;
锁(_流)
{
wait=!\u dataIsReady.IsSet&&!\u noMoreAdditions;
}
如果(等待)
{
_dataIsReady.Wait();
}
锁(_流)
{
如果(!\u nomore添加)
_dataIsReady.Reset();
如果
IEnumerable<SomeType> collection = ...
clannel.Method(collection.ToStream());
public void Method(Stream stream){
IEnumerable<SomeType> coll = stream.FromStream<SomeType>();
}