Activator.Creat eInstance Question

Johnny R

Hello,

I'm loading a Class from Assemly DLL using Activator.Creat eInstance.
That loaded Class is executed in a worker Thread with no loop.

What actually happends when class is loaded using Activator.Creat eInstance?

If I create same class using Activator.Creat eInstance many times will
there be multiple instances of that same class created by
Activator.Creat eInstance?

If Activator.Creat eInstance will create multiple classes when will those
instances of class be deleted? Do I have to use certain API to delete them
or will they be garbage collected after they are coming out of scope?

Code like below:

{ // Start of Block, scope begings
object baseObject = Activator.Creat eInstance (type);
..
..
} // End of Block, scope ends
....

Will Class created above deleted here when it comes out of scope?

Second question is that if I want that object created by
Activator.Creat eInstance
is in memory permanently how will I do it? Is it possible to get reference
to
same instance using certain API?

If anyone can give any answers or links to documents containing info I will
appraise it.

Cheers,

Jan 10 '07 #1

Subscribe Reply

11537

Bob Powell [MVP]

See answers inline...

--
Bob Powell [MVP]
Visual C#, System.Drawing

Ramuseco Limited .NET consulting
http://www.ramuseco.com

Find great Windows Forms articles in Windows Forms Tips and Tricks
http://www.bobpowell.net/tipstricks.htm

Answer those GDI+ questions with the GDI+ FAQ
http://www.bobpowell.net/faqmain.htm

All new articles provide code in C# and VB.NET.
Subscribe to the RSS feeds provided and never miss a new article.

Johnny R wrote:

Hello,

I'm loading a Class from Assemly DLL using Activator.Creat eInstance.
That loaded Class is executed in a worker Thread with no loop.

What actually happends when class is loaded using Activator.Creat eInstance?

Reflection is used to find the default parameterless constructor and to
run it.

>
If I create same class using Activator.Creat eInstance many times will
there be multiple instances of that same class created by
Activator.Creat eInstance?

Yes.

>
If Activator.Creat eInstance will create multiple classes when will those
instances of class be deleted? Do I have to use certain API to delete them
or will they be garbage collected after they are coming out of scope?

Depends on the class. Like all objects you may have some resource issues
to clean up. You should decide whether to implement IDisposable for example.

Generally a simple class will be collected once there are no references
to it any more.

>
Code like below:

{ // Start of Block, scope begings
object baseObject = Activator.Creat eInstance (type);
..
..
} // End of Block, scope ends
...

Will Class created above deleted here when it comes out of scope?

yes. Activation is no different really to the new keyword.

>
Second question is that if I want that object created by
Activator.Creat eInstance
is in memory permanently how will I do it? Is it possible to get reference
to
same instance using certain API?

You can use a singleton pattern for any object.

>
If anyone can give any answers or links to documents containing info I will
appraise it.

Cheers,

Jan 11 '07 #2

Similar topics

3352

Activator.CreateInstance() versus 'new'

by: David Sworder | last post by:

Hi, I need to design a method that creates and returns a large array of objects. The problem is that the *type* of object to create isn't know until runtime. As a result, a parameter of type "Type" must be passed in: IMyInterface CreateObjects(Type type,int numberOfObjects); Internally this method will call Activator.CreateInstance() to create the objects. Here's my question: Is there a significant performance penalty

.NET Framework

505

Activator.CreateInstance Method

by: shmeian | last post by:

I have the following code which works fine. However I want to pass the object I'm instantiating a string for its constructor. I can't get the syntax right. Can someone give me an example of Activator.CreateInstance where they pass an argument with the object type? Assembly a = Assembly.GetExecutingAssembly(); Type type = a.GetType("MyAssemb.MyClass"); Object o = Activator.CreateInstance(type); MyClass myObj=...

.NET Framework

12032

"Constructor not found" exception using Activator.CreateInstance. Is InvokeMember a better choice?

by: hazz | last post by:

this is a repost with more concise code (well, for me) and better questions (I hope....) . given the following two classes, my intent is to use either Activator.CreateInstance or InvokeMember pass a token into the instantiated class DBPassword and return a string; ************************************** namespace DBPasswordProvider public class DBPassword {

C# / C Sharp

15340

Difference Between assembly.CreateInstance and System.Activator.CreateInstance

by: John Jenkins | last post by:

Hi, I have a fairly simeple question. What are the differences between Assembly.CreateInstance and System.Activator.CreateInstance? I had read that one maps to the other, however when I use Assembly.CreateInstance to create an object that implements an interface it cannot cast to the appropriate interface type before returning. e.g. ISubmit lo_MessagingObject=null; string

C# / C Sharp

17070

System.Reflection Activator.CreateInstance

by: System.Reflection Activator | last post by:

************************************** //Load the Assembly Assembly a = Assembly.LoadFrom(sAssembly); //Get Types so we can Identify the Interface. Type mytypes = a.GetTypes(); BindingFlags flags = (BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Static | BindingFlags.Instance | BindingFlags.DeclaredOnly); //Iterate through the Assembly to find Class with a Public Interface.

C# / C Sharp

4764

Activator.CreateInstance or InvokeMember? Code is not getting me where I want to go.

by: hazz | last post by:

this is a repost with a hopefully more clearly stated scenario and more concise questions at the end. given the following two classes, my intent is to use pass a token into the instantiated class DBPassword and return a string; ************************************** public class DBPassword { public DBPassword() { //Empty constructor

.NET Framework

1417

Activator Question

by: Dan Dorey | last post by:

My goal is to pass in an assembly and have the method return an instance of any classes that inherit from the generic type T. My problem is that I'm unable to cast from the result of Activator.CreateInstance(curType) to T even though curType is a concrete class of T (T is abstract in this case). I'm unsure why I can't make this cast. In another method where I don't have the restriction of T being a class, this approch works fine when T...

C# / C Sharp

1433

Re: activator classes n createInstance()

by: Jon Skeet [C# MVP] | last post by:

On Apr 11, 8:40 am, Andrew <And...@discussions.microsoft.comwrote: Okay, that means you've either not given the full classname (including namespace) or it's not in mscorlib or the currently executing assembly, in which case you need to give assembly details as well. The line with testType2 is explicitly trying to find a class called "name". The string "name" and the variable called name are completely independent things.

C# / C Sharp

1297

RE: activator classes n createInstance()

by: =?Utf-8?B?QW5kcmV3?= | last post by:

Found it. string name = Properties.Settings.Default.ClassName.ToString(); //"myproject.myclass, myassembly" format. //name = "ABC.MyClass, Assem" ; Type t = Type.GetType(name); Object obj = Activator.CreateInstance(t); string result = t.InvokeMember("methodName",

C# / C Sharp

9563

What is ONU?

by: marktang | last post by:

ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However, people are often confused as to whether an ONU can Work As a Router. In this blog post, we’ll explore What is ONU, What Is Router, ONU & Router’s main usage, and What is the difference between ONU and Router. Let’s take a closer look ! Part I. Meaning of...

General

9998

Maximizing Business Potential: The Nexus of Website Design and Digital Marketing

by: jinu1996 | last post by:

In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven tapestry of website design and digital marketing. It's not merely about having a website; it's about crafting an immersive digital experience that captivates audiences and drives business growth. The Art of Business Website Design Your website is...

Online Marketing

9938

The easy way to turn off automatic updates for Windows 10/11

by: Hystou | last post by:

Overview: Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...

Windows Server

8822

AI Job Threat for Devs

by: agi2029 | last post by:

Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then launch it, all on its own.... Now, this would greatly impact the work of software developers. The idea...

Career Advice

7366

Access Europe - Using VBA to create a class based on a table - Wed 1 May

by: isladogs | last post by:

The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome a new presenter, Adolph Dupré who will be discussing some powerful techniques for using class modules. He will explain when you may want to use classes instead of User Defined Types (UDT). For example, to manage the data in unbound forms. Adolph will...

Microsoft Access / VBA

5270

Trying to create a lan-to-lan vpn between two differents networks

by: TSSRALBI | last post by:

Hello I'm a network technician in training and I need your help. I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs. The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols. I succeeded, with both firewalls in the same network. But I'm wondering if it's possible to do the same thing, with 2 Pfsense firewalls...

Networking - Hardware / Configuration

5406

Windows Forms - .Net 8.0

by: adsilva | last post by:

A Windows Forms form does not have the event Unload, like VB6. What one acts like?

Visual Basic .NET

3917

transfer the data from one system to another through ip address

by: 6302768590 | last post by:

Hai team i want code for transfer the data from one system to another through IP address by using C# our system has to for every 5mins then we have to update the data what the data is updated we have to send another system

C# / C Sharp

2793

Comprehensive Guide to Website Development in Toronto: Expert Insights from BSMN Consultancy

by: bsmnconsultancy | last post by:

In today's digital era, a well-designed website is crucial for businesses looking to succeed. Whether you're a small business owner or a large corporation in Toronto, having a strong online presence can significantly impact your brand's success. BSMN Consultancy, a leader in Website Development in Toronto offers valuable insights into creating effective websites that not only look great but also perform exceptionally well. In this comprehensive...

General