obtain ref to assembly from created class instance

[John Grandy]

It does not seem possible to compare instances of assemblies from which
instances of controls/classes are created.

In other words, if I have

Assembly myAssembly Assembly.LoadFrom(path);
object myClass = myAssembly.CreateInstance("<ClassName>");

It is not possible to obtain a reference to myAssembly from myClass ...

 

[Bruce Wood]

It does not seem possible to compare instances of assemblies from which
instances of controls/classes are created.

In other words, if I have

Assembly myAssembly Assembly.LoadFrom(path);
object myClass = myAssembly.CreateInstance("<ClassName>");

It is not possible to obtain a reference to myAssembly from myClass ...

How about

Assembly a = myClass.GetType().Assembly;

?

 

[John Grandy]

I wonder if myClass.GetType().Assembly returns the assembly instance from
which the object was created ( via Assembly.CreateInstance() ), or if it
returns a new instance of the assembly associated with the object's type.

In other words, if two class instances were created respectively from two
instances of the same assembly, then does

myClass1.GetType().Assembly == myClass2.GetType().Assembly

return true or false ?

 

[Jon Skeet [C# MVP]]

I wonder if myClass.GetType().Assembly returns the assembly instance from
which the object was created ( via Assembly.CreateInstance() ), or if it
returns a new instance of the assembly associated with the object's type.

In other words, if two class instances were created respectively from two
instances of the same assembly, then does

myClass1.GetType().Assembly == myClass2.GetType().Assembly

return true or false ?

True, always - and GetType() will always return the same Type reference
too.

 

[John Grandy]

Is there any other way to test whether two instances of a class were created
from different instances of the same assembly type ? Or do class instances
not have "memory" of how they were created ?

 

[Jon Skeet [C# MVP]]

Is there any other way to test whether two instances of a class were created
from different instances of the same assembly type ? Or do class instances
not have "memory" of how they were created ?

No, they do:

if (a.GetType() != b.GetType())

will compare the types including which assemblies they were loaded
from.

 

[John Grandy]

Here is what I'm finding in practice :
Assembly assembly1 = Assembly.LoadFrom( assemblyPath );

Assembly assembly2 = Assembly.LoadFrom( assemblyPath );

object instance1 = assembly1.CreateInstance( className );

object instance2 = assembly2.CreateInstance( className );

Assert.IsTrue( instance1.GetType() == instance2.GetType(), "Assert.IsTrue:
instance1.GetType() == instance2.GetType()" );

The assert does not throw an exception.

 

[Jon Skeet [C# MVP]]

Here is what I'm finding in practice :
Assembly assembly1 = Assembly.LoadFrom( assemblyPath );

Assembly assembly2 = Assembly.LoadFrom( assemblyPath );

object instance1 = assembly1.CreateInstance( className );

object instance2 = assembly2.CreateInstance( className );

Assert.IsTrue( instance1.GetType() == instance2.GetType(), "Assert.IsTrue:
instance1.GetType() == instance2.GetType()" );

The assert does not throw an exception.

I suspect you'll find that assembly1==assembly2 then as well.