如何使用MongoDB C＃序列化器序列化值类型？

Question

Mongodb C＃驱动程序不会序列化结构/值类型。如何才能做到这一点？

Answer 1

您可以创建自定义序列使用该代码来处理结构：

public class StructBsonSerializer : IBsonSerializer 
{ 
    public void Serialize(BsonWriter bsonWriter, Type nominalType, object value, IBsonSerializationOptions options) 
    { 
     var fields = nominalType.GetFields(BindingFlags.Instance | BindingFlags.Public); 
     var propsAll = nominalType.GetProperties(BindingFlags.Instance | BindingFlags.Public); 

     var props = new List<PropertyInfo>(); 
     foreach (var prop in propsAll) 
     { 
      if (prop.CanWrite) 
      { 
       props.Add(prop); 
      } 
     } 

     bsonWriter.WriteStartDocument(); 

     foreach (var field in fields) 
     { 
      bsonWriter.WriteName(field.Name); 
      BsonSerializer.Serialize(bsonWriter, field.FieldType, field.GetValue(value)); 
     } 
     foreach (var prop in props) 
     { 
      bsonWriter.WriteName(prop.Name); 
      BsonSerializer.Serialize(bsonWriter, prop.PropertyType, prop.GetValue(value, null)); 
     } 

     bsonWriter.WriteEndDocument(); 
    } 

    public object Deserialize(BsonReader bsonReader, Type nominalType, Type actualType, IBsonSerializationOptions options) 
    { 
     var obj = Activator.CreateInstance(actualType); 

     bsonReader.ReadStartDocument(); 

     while (bsonReader.ReadBsonType() != BsonType.EndOfDocument) 
     { 
      var name = bsonReader.ReadName(); 

      var field = actualType.GetField(name); 
      if (field != null) 
      { 
       var value = BsonSerializer.Deserialize(bsonReader, field.FieldType); 
       field.SetValue(obj, value); 
      } 

      var prop = actualType.GetProperty(name); 
      if (prop != null) 
      { 
       var value = BsonSerializer.Deserialize(bsonReader, prop.PropertyType); 
       prop.SetValue(obj, value, null); 
      } 
     } 

     bsonReader.ReadEndDocument(); 

     return obj; 
    } 

    public object Deserialize(BsonReader bsonReader, Type nominalType, IBsonSerializationOptions options) 
    { 
     return Deserialize(bsonReader, nominalType, nominalType, options); 
    } 

    public bool GetDocumentId(object document, out object id, out Type idNominalType, out IIdGenerator idGenerator) 
    { 
     throw new NotImplementedException(); 
    } 

    public void SetDocumentId(object document, object id) 
    { 
     throw new NotImplementedException(); 
    } 
} 

然后，注册即串行器为你的结构：

BsonSerializer.RegisterSerializer(typeof(MyStruct), new StructBsonSerializer()); 

Answer 2

基于上面的代码我管理，以使其适应Mongo Driver版本2.2.3。

public class BasicStructSerializer<T> : StructSerializerBase<T> where T: struct 
{ 
    public override void Serialize(BsonSerializationContext context, BsonSerializationArgs args, T value) 
    { 
     var nominalType = args.NominalType; 
     var fields = nominalType.GetFields(BindingFlags.Instance | BindingFlags.Public); 
     var propsAll = nominalType.GetProperties(BindingFlags.Instance | BindingFlags.Public); 

     var props = new List<PropertyInfo>(); 
     foreach (var prop in propsAll) 
     { 
      if (prop.CanWrite) 
      { 
       props.Add(prop); 
      } 
     } 

     var bsonWriter = context.Writer; 

     bsonWriter.WriteStartDocument(); 

     foreach (var field in fields) 
     { 
      bsonWriter.WriteName(field.Name); 
      BsonSerializer.Serialize(bsonWriter, field.FieldType, field.GetValue(value)); 
     } 
     foreach (var prop in props) 
     { 
      bsonWriter.WriteName(prop.Name); 
      BsonSerializer.Serialize(bsonWriter, prop.PropertyType, prop.GetValue(value, null)); 
     } 

     bsonWriter.WriteEndDocument(); 
    } 

    public override T Deserialize(BsonDeserializationContext context, BsonDeserializationArgs args) 
    { 
     //boxing is required for SetValue to work 
     var obj = (object)(new T()); 
     var actualType = args.NominalType; 
     var bsonReader = context.Reader; 

     bsonReader.ReadStartDocument(); 

     while (bsonReader.ReadBsonType() != BsonType.EndOfDocument) 
     { 
      var name = bsonReader.ReadName(); 

      var field = actualType.GetField(name); 
      if (field != null) 
      { 
       var value = BsonSerializer.Deserialize(bsonReader, field.FieldType); 
       field.SetValue(obj, value); 
      } 

      var prop = actualType.GetProperty(name); 
      if (prop != null) 
      { 
       var value = BsonSerializer.Deserialize(bsonReader, prop.PropertyType); 
       prop.SetValue(obj, value, null); 
      } 
     } 

     bsonReader.ReadEndDocument(); 

     return (T)obj; 
    } 
} 

用法：

cm.GetMemberMap(c => c.SomeMemberName).SetSerializer(new BasicStructSerializer<SomeMemberType>());