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object to byte[] in c#

Hi All!

I'm working with c# and would like to put an object type into a byte[]. I found some documentation on how to put a struct into a buffer and how to dynamically allocate memory to copy a void* to another void*, but not how to copy an object into a buffer. I also looked at MemoryStream and BitConverter. If anyone has any ideas, I'm more than happy to hear them!

Thanks!

choo_chu

Ravi Singh

Hi, do you want to write the object out to disk and then later read it back in? I think your refering to serialization, this article gives a good explanation using the BinaryFormatter class:

http://www.codeproject.com/csharp/objserial.asp

choo_chu

ASKER

I have looked at the BinaryFormatter, but I'm not looking for serialization because I don't need all the extra information that is needed to reproduce the class when it's deserialized. I just need the data. (Notice that sizeof() and the amount of bytes used to serialize and object aren't the same.) In c++, what I'm looking for would be akin to memcpy().

Thanks!

choo_chu

yotamsher

Hey choo_chu

what does your class look like?
I got the feeling, that it is more like a struct, can't you just write a ToByteArray and FromByteArray functions?
why do you need to memcpy? are you then transfering it somewhere?

the more details you give, the better answers you'll get

Yotam

choo_chu

ASKER

Hi,

I won't know what the incoming object looks like, I will only know its size. The constructor has the following definition:
DBObject( object obj, int size )

The class DBObject is the class of objects that are in the nodes of a b-tree. The class contains two data members, _size and _data. The constructor will set values _size = size and _data = obj...I want to be able to copy obj into _data, which is a byte[]. The data in this object (_size and _data) will be written to file and later retrieved.

Thanks!

choo_chu

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yotamsher

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choo_chu

ASKER

Thanks for the article Yotam...I think that will help a lot. I'll keep you posted.

choo_chu

choo_chu

ASKER

Ok, I figured out how to do what I want using reflection...it's actually kinda neat ;) This isn't all the code, but is the jist of what I did. I got the field type, and I stuff the values into the byte[] using BitConverter.GetBytes(). When I get to the byte[] type, I just use the GetValue() supplied by the FieldInfo. Mind you this is test code, so it doesn't pay attention to where in the byte[] it is putting things, it is just over writing previous values. It is just so I could see whether this idea would actually work.

                              // copy to byte[]
                              switch( fieldType )
                              {
                                    case( "System.Int32" ): // int or long
                                          if( fi[c].Name.ToString() == "_size" )
                                          {
                                                size = (int)fi[c].GetValue( obj );
                                          }
                                          _data = BitConverter.GetBytes( size );
                                          break;
                                    case( "System.Int64" ):
                                          _data = BitConverter.GetBytes( (long)fi[c].GetValue( obj ) );
                                          break;
                                    case( "System.Boolean" ):
                                          _data = BitConverter.GetBytes( (bool)fi[c].GetValue( obj ) );
                                          break;
:
:

Thanks a lot for your input!

choo_chu