Да, вы можете сделать это. С оговорками.
Пример сериализации метода с yield, десериализации и продолжения можно найти здесь: http://www.agilekiwi.com/dotnet/CountingDemo.cs ( Ссылка веб-архива ).
Как правило, попытка сериализации без дополнительной работы завершится неудачей. Это связано с тем, что сгенерированные компилятором классы не помечены атрибутом Serializable. Однако вы можете обойти это.
Я хотел бы отметить, что причина, по которой они не помечены сериализуемыми, заключается в том, что они являются деталями реализации и могут привести к серьезным изменениям в будущих версиях, поэтому вы не сможете десериализовать их в более новой версии.
Относительно вопроса, который я задал на , как сериализовать анонимных делегатов , что должно работать и в этом случае.
Вот исходный код "хака":
// Copyright © 2007 John M Rusk (http://www.agilekiwi.com)
//
// You may use this source code in any manner you wish, subject to
// the following conditions:
//
// (a) The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// (b) THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Reflection;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Soap;
namespace AgileKiwi.PersistentIterator.Demo
{
/// <summary>
/// This is the class we will enumerate over
/// </summary>
[Serializable]
public class SimpleEnumerable
{
public IEnumerator<string> Foo()
{
yield return "One";
yield return "Two";
yield return "Three";
}
#region Here is a more advanced example
// This shows that the solution even works for iterators which call other iterators
// See SimpleFoo below for a simpler example
public IEnumerator<string> AdvancedFoo()
{
yield return "One";
foreach (string s in Letters())
yield return "Two " + s;
yield return "Three";
}
private IEnumerable<string> Letters()
{
yield return "a";
yield return "b";
yield return "c";
}
#endregion
}
/// <summary>
/// This is the command-line program which calls the iterator and serializes the state
/// </summary>
public class Program
{
public static void Main()
{
// Create/restore the iterator
IEnumerator<string> e;
if (File.Exists(StateFile))
e = LoadIterator();
else
e = (new SimpleEnumerable()).Foo(); // start new iterator
// Move to next item and display it.
// We can't use foreach here, because we only want to get ONE
// result at a time.
if (e.MoveNext())
Console.WriteLine(e.Current);
else
Console.WriteLine("Finished. Delete the state.xml file to restart");
// Save the iterator state back to the file
SaveIterator(e);
// Pause if running from the IDE
if (Debugger.IsAttached)
{
Console.Write("Press any key...");
Console.ReadKey();
}
}
static string StateFile
{
get {
return Path.Combine(
Path.GetDirectoryName(Assembly.GetEntryAssembly().Location),
"State.xml");
}
}
static IEnumerator<string> LoadIterator()
{
using (FileStream stream = new FileStream(StateFile, FileMode.Open))
{
ISurrogateSelector selector = new EnumerationSurrogateSelector();
IFormatter f = new SoapFormatter(selector, new StreamingContext());
return (IEnumerator<string>)f.Deserialize(stream);
}
}
static void SaveIterator(IEnumerator<string> e)
{
using (FileStream stream = new FileStream(StateFile, FileMode.Create))
{
ISurrogateSelector selector = new EnumerationSurrogateSelector();
IFormatter f = new SoapFormatter(selector, new StreamingContext());
f.Serialize(stream, e);
}
#region Note: The above code puts the name of the compiler-generated enumerator class...
// into the serialized output. Under what circumstances, if any, might a recompile result in
// a different class name? I have not yet investigated what the answer might be.
// I suspect MS provide no guarantees in that regard.
#endregion
}
}
#region Helper classes to serialize iterator state
// See http://msdn.microsoft.com/msdnmag/issues/02/09/net/#S3
class EnumerationSurrogateSelector : ISurrogateSelector
{
ISurrogateSelector _next;
public void ChainSelector(ISurrogateSelector selector)
{
_next = selector;
}
public ISurrogateSelector GetNextSelector()
{
return _next;
}
public ISerializationSurrogate GetSurrogate(Type type, StreamingContext context, out ISurrogateSelector selector)
{
if (typeof(System.Collections.IEnumerator).IsAssignableFrom(type))
{
selector = this;
return new EnumeratorSerializationSurrogate();
}
else
{
//todo: check this section
if (_next == null)
{
selector = null;
return null;
}
else
{
return _next.GetSurrogate(type, context, out selector);
}
}
}
}
// see http://msdn.microsoft.com/msdnmag/issues/02/09/net/#S3
class EnumeratorSerializationSurrogate : ISerializationSurrogate
{
public void GetObjectData(object obj, SerializationInfo info, StreamingContext context)
{
foreach(FieldInfo f in obj.GetType().GetFields(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic))
info.AddValue(f.Name, f.GetValue(obj));
}
public object SetObjectData(object obj, SerializationInfo info, StreamingContext context,
ISurrogateSelector selector)
{
foreach (FieldInfo f in obj.GetType().GetFields(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic))
f.SetValue(obj, info.GetValue(f.Name, f.FieldType));
return obj;
}
}
#endregion
}