Serialization and de-serialization of types loaded from assembly at runtime

[mookid8000]

Hi group!

Is it possible to scan an assembly *which has NOT been added as a
reference* for types, and dynamically create instances of the loaded
types?

I have a program, MyProgram.exe, which at runtime uses
Asseembly.LoadF ile(...) to load an assembly, MyAssembly.dll. When
MyAssembly.dll is added as a reference to the MyProgram project,
serialization and de-serialization works lige a charm.

However, when I remove the reference to MyAssembly.dll in the MyProgram
project, I get an exception upon de-serialization.

Is there something I can do which is like "adding an assembly as a
reference at runtime"?

The best,
Mogens

[Milosz Skalecki]

Howdy,

Yes it's possible and quite simple. Have a look at my short C# example

private void button3_Click(o bject sender, System.EventArg s e)
{

System.Reflecti on.Assembly assembly
=
System.Reflecti on.Assembly.Loa dFile("C:\\WIND OWS\\assembly\\ GAC\\Microsoft. VisualBasic\\7. 0.5000.0__b03f5 f7f11d50a3a\\Mi crosoft.VisualB asic.dll");

listBox1.BeginU pdate();
foreach (System.Type type in assembly.GetExp ortedTypes())
{
listBox1.Items. Add(type.FullNa me);
if (type.IsClass && !type.IsAbstrac t)
{
object instance = System.Activato r.CreateInstanc e(type);
}
}
listBox1.EndUpd ate();

}
--
Milosz Skalecki
MCP, MCAD
"mo********@gma il.com" wrote:

Hi group!

Is it possible to scan an assembly *which has NOT been added as a
reference* for types, and dynamically create instances of the loaded
types?

I have a program, MyProgram.exe, which at runtime uses
Asseembly.LoadF ile(...) to load an assembly, MyAssembly.dll. When
MyAssembly.dll is added as a reference to the MyProgram project,
serialization and de-serialization works lige a charm.

However, when I remove the reference to MyAssembly.dll in the MyProgram
project, I get an exception upon de-serialization.

Is there something I can do which is like "adding an assembly as a
reference at runtime"?

The best,
Mogens

[Nicolas Guinet]

> Is it possible to scan an assembly *which has NOT been added as a

reference* for types, and dynamically create instances of the loaded
types?
YES IT IS

something like this (untested) :

Assembly myAss = Assembly.Load(" myDll.dll");

Type t = myAss.GetType(" namespacemyDll. typeName");
ConstructorInfo ci = new t.GetConstructo r( new t[0] );
object o = ConstructorInfo .Invoke( new object[0] );
// now o is a ref. to an anstance of namespacemyDll. typeName

or

foreach( Type t in myAss.GetTypes( ) )
{
Console.WriteLi ne( "object: " + t.ToString() );
object o = Activator.Creat eInstance(type) ;
// and so on ....foreach( MethodInfo m in t.GetMethods() ....
}
Nicolas Guinet
www.nicolasguinet.com

<mo********@gma il.com> a écrit dans le message de news:
11************* ********@u72g20 00...legro ups.com... Hi group!

Is it possible to scan an assembly *which has NOT been added as a
reference* for types, and dynamically create instances of the loaded
types?

I have a program, MyProgram.exe, which at runtime uses
Asseembly.LoadF ile(...) to load an assembly, MyAssembly.dll. When
MyAssembly.dll is added as a reference to the MyProgram project,
serialization and de-serialization works lige a charm.

However, when I remove the reference to MyAssembly.dll in the MyProgram
project, I get an exception upon de-serialization.

Is there something I can do which is like "adding an assembly as a
reference at runtime"?

The best,
Mogens

[mookid8000]

Thanks for the replies guys, but I think neither of you really
understood my problem.

I do use Assembly.LoadFi le to load an assembly, and I do use
GetExportedType s to iterate through all types and look for subclasses
of one particular class.

The problem arises when the user of my program saves his work. At this
point all instances of the dynamically loaded types will be serialized
into a file.

Now, when the user quits the program and tries to load his work, a
SerializationEx ception occurs.

I can solve my problem temporarily by adding the assemblies I want to
load at runtime as references to the project, but this does not solve
my problem entirely, because I want to be able to load the assemblies
truly at runtime.

[Yury]

You should make XmlSerializer aware of all types in your objects net.
Use following constructor to specify extra types.

System.Xml.Seri alization.XmlSe rializer(Type type, Type [] extraTypes)

[David Levine]

You can subscribe to the AssemblyResolve event; the deserializer will
generate an event for each assembly that needs to be loaded.

<mo********@gma il.com> wrote in message
news:11******** **************@ i39g2000cwa.goo glegroups.com.. .

Thanks for the replies guys, but I think neither of you really
understood my problem.

I do use Assembly.LoadFi le to load an assembly, and I do use
GetExportedType s to iterate through all types and look for subclasses
of one particular class.

The problem arises when the user of my program saves his work. At this
point all instances of the dynamically loaded types will be serialized
into a file.

Now, when the user quits the program and tries to load his work, a
SerializationEx ception occurs.

I can solve my problem temporarily by adding the assemblies I want to
load at runtime as references to the project, but this does not solve
my problem entirely, because I want to be able to load the assemblies
truly at runtime.

[mookid8000]

I did this, and it seems to work most of the time. However, it seems
sometimes the event handler does not get called when it should. But I
will figure out why that is on my own...

Thanks for the quick reply!

-Mogens