asynchronous call

c# delegate begininvoke

1. Asynchronous Programming Overview

The .NET Framework allows you to call any method asynchronously. Define a delegate with the same signature as the method you want to call; the common language runtime automatically defines BeginInvoke and EndInvoke methods for this delegate, with the appropriate signatures.

2. Calling Synchronous Methods Asynchronously

.NET enables you to call any method asynchronously. To do this, you define a delegate with the same signature as the method you want to call. The common language runtime automatically defines BeginInvoke and EndInvoke methods for this delegate, with the appropriate signatures.

3. Call a Method Asynchronously using Delegate BeginInvoke and EndInvoke Pattern

Abstract: In this article, we will explore multiple ways to call a method asynchronously using Delegates. You can call methods asynchronously in four different ways using the BeginInvoke() and EndInvoke() methods of the Delegate class

In this article, we will explore multiple ways to call a method asynchronously using Delegates. You can call methods asynchronously in four different ways using the BeginInvoke() and EndInvoke() methods of the Delegate class. The four different ways are using the EndInvoke pattern, WaitHandle, Polling pattern and using a Callback Pattern. In this article, we will see the Delegate EndInvoke Pattern. In the subsequent articles, we will explore the Polling Pattern and Callback pattern.

A delegate is a special method that encapsulates a method and represents a method signature. From the main thread, when a method is invoked using a delegate, the Main thread has to wait until the method, that was invoked, has completed. This could prove expensive if your code is performing a slow operation like downloading a large file from your server.

4. Difference between delegate.BeginInvoke and using ThreadPool threads in C#

In C# is there any difference between using a delegate to do some work asynchronously (calling BeginInvoke()) and using a ThreadPool thread as shown below

5. Use BeginInvoke and EndInvoke to perform tasks asynchronously in C#

This example uses the Emboss method to create embossed images. How that method works isn’t important to the discussion of working asynchronously so it isn’t covered here. Download the example to see how it works. The only thing about that method that matters for this discussion is that it is slow so running it on multiple cores or CPUs can save time.

Good Case Study

6. BeginInvoke with delegate

I've been doing some reading tonight on async delegate method invocations and I'm not too clear on what's going on under the hood with delegate.BeginInvoke() but I wanted to know if someone can tell me if there are any performance differences between these two code blocks as far as using an AsyncCallback and not using an AsyncCallback and take into consideration that I'm updating the GUI winForm intensively (multiple times per sec):

7. What's up with BeginInvoke?

Why and when to use Control.BeginInvoke()?

8. Simple Blocking Queue for Thread Communication and Inter-thread Invocation

A generic class to be used as a conveyor for data and tasks between threads

9. Asynchronous Delegates

Sometimes it is desirable to call a method asynchronously, so the call returns immediately while the method executes on a separate thread. The runtime provides a standard way that any method can be called asynchronously, taking into account retrieving return values and ref/in parameters supplied to the method. When the C# compiler encounters a delegate, the delegate derived class it generates contains three key methods:

10. Asynchronous Calls in .NET

When you make a method call on an object, typically you must block the client while the object executes the call, and control returns to the client only when the method completes execution and returns.

11. Detailed explanation of using Invoke and BeginInvoke in C# form

In the use of Invoke or BeginInvoke, the delegate delegate is used without exception. As for the essence of delegate, please refer to my other essay: Views on .net events .

12. C: delegate BeginInvoke as asynchronous thread

In an application scenario, the browser uploads a file, and the file background calls for file conversion, which takes quite a long time. In this way, if a thread is synchronized, the user feels stuck on the browser. The card card card card, here we use the entrusted BeginInvoke and endinvoke methods to operate the thread. The BeginInvoke method can use different threads. Step through the method the delegate points to. Then get the return value of the method through the endinvoke method (the return value of the endinvoke method is the return value of the called method), or make sure that the method has been successfully called. To put it plainly, it is equivalent to opening a multithread. After your user file is saved, the response returns. This BeginInvoke asynchronously executes the delegate method. After that, execute your asynchrony callback function. Number;

13. How to perform C# Asynchronous operations

In this article I will discuss about the different ways in which we can perform a long running operation asynchronously in C#. I will discuss all the cases with examples. This will help you to decide which method you can opt for while working asynchronous programming.

14. Invoking Methods Asynchronously Using Delegates

Asynchronous operation improves the program responsiveness and availability. In my past article titled Asynchronous Programming In .NET , I explained how to design your components with built-in support for asynchronous operations. But what if some one has already developed the component and that too without asynchronous programming support? In such cases delegates can come to the rescue. In fact that is the topic of this article.

15. How delegate can be used for callback in c#?what is Asynchronous Delegate?

Consider below example where delegate is pointing to function which is time consuming.

16. C# – Asynchronous Programming using BeginInvoke

In C#, delegates automatically get the BeginInvoke and EndInvoke methods defined for them. BeginInvoke is used for running the processes defined by the method and assigned to the delegate on a different thread (asynchronously).

The BeginInvoke method takes a AsyncCallback delegate parameter as a callback method. A common misconception about the BeginInvoke method is that if one does not care about when the method invoked by BeginInvoke completes or its return value, then one can pass in null for this method. THIS IS WRONG! and is partly based on old documentation. If you look at this MSDN document, you can clearly see that the EndInvoke method is not optional but required.

Good Examples

17. Delegates And Async Programming

Recall that the .Net delegate type is essentially a type-safe, object oriented, function pointer. Let's get into a bit more detail about it. When you declare a .Net delegate, the C# compiler responds by building a sealed class that derives from the System.MulticastDelegate with the ability to maintain a list of method addresses, all of which may be invoked at a time or a later time.

18. Delegate And Async Programming C# (AsyncCallback And Object State)

continued post. I'm using the same example as in my previous article, so the following are all the terms and code from the previous example:

19. Asynchronous Calls in .NET

However, there are quite a few cases where you want to call methods asynchronously?that is, you want control to return immediately to the client while the object executes the called method in the background, and then somehow let the client know when the method execution is completed. Such an execution mode is called asynchronous method invocation and the action is an asynchronous call. Asynchronous calls allow you to improve availability, increase throughput and performance, and make your applications more scalable.

20. 2 Ways to Implement Asynchronous Technique in C#

1)Implement by delegate. 2)Using C# 5.0, async and await keyword

A few days ago in our organization we were trying to implement asynchronous programming (obviously in C# with Visual Studio 2010). First of all Visual Studio 2010 targets the .NET framework 4.0 and asynchronous programming is the concept of C# 5.0 that demands .NET framework 4.5 to compile and run.

21. What is AsyncCallback?

What is the use of AsyncCallback and why should we use it?

Demo to pick asynchronous programming quickly

22. IAsyncResult Interface

very good example to understand IAsyncResult usage.

Represents the status of an asynchronous operation.

The following example demonstrates how to use the AsyncWaitHandle property to get a WaitHandle, and how to wait for an asynchronous call on a delegate. The WaitHandle is signaled when the asynchronous call completes, and you can wait for it by calling the WaitOne method.

23. AsyncResult Class

Encapsulates the results of an asynchronous operation on a delegate.

Inheritance: Object ->AsyncResult
Attributes:ComVisibleAttribute
Implements: IAsyncResult , IMessageSink

24. Asynchronous Programming Using Delegates

Delegates enable you to call a synchronous method in an asynchronous manner. When you call a delegate synchronously, the Invoke method calls the target method directly on the current thread. If the BeginInvoke method is called, the common language runtime (CLR) queues the request and returns immediately to the caller. The target method is called asynchronously on a thread from the thread pool. The original thread, which submitted the request, is free to continue executing in parallel with the target method. If a callback method has been specified in the call to the BeginInvoke method, the callback method is called when the target method ends. In the callback method, the EndInvoke method obtains the return value and any input/output or output-only parameters. If no callback method is specified when calling BeginInvoke, EndInvoke can be called from the thread that call

25. Calling Synchronous Methods Asynchronously

Important No matter which technique you use, always call EndInvoke to complete your asynchronous call.

the same as item 2. it has good examples to show 4 ways to make asynchronous call.

.NET enables you to call any method asynchronously. To do this, you define a delegate with the same signature as the method you want to call. The common language runtime automatically defines BeginInvoke and EndInvoke methods for this delegate, with the appropriate signatures.

The code examples in this topic demonstrate four common ways to use BeginInvoke and EndInvoke to make asynchronous calls. After calling BeginInvoke you can do the following:

1. Do some work and then call EndInvoke to block until the call completes.
2. Obtain a WaitHandle using the IAsyncResult.AsyncWaitHandle property, use its WaitOne method to block execution until the WaitHandle is signaled, and then call EndInvoke.
3. Poll the IAsyncResult returned by BeginInvoke to determine when the asynchronous call has completed, and then call EndInvoke.
4. Pass a delegate for a callback method to BeginInvoke. The method is executed on a ThreadPool thread when the asynchronous call completes. The callback method calls EndInvoke.
26. Asynchronous Method Invocation

How to use .NET to call methods in a non-blocking mode.

27. Asynchronous Programming Model (APM)

An asynchronous operation that uses the IAsyncResult design pattern is implemented as two methods named BeginOperationName and EndOperationName that begin and end the asynchronous operation OperationName respectively. For example, the FileStream class provides the BeginRead and EndRead methods to asynchronously read bytes from a file. These methods implement the asynchronous version of the Read method.

28. What's up with BeginInvoke?

Why and when to use Control.BeginInvoke()?

You are developing this shiny new multithreaded .NET application that has this spanking new UI. You are done coding and it's time for giving a demo to your boss. And while running the demo, the UI hangs. Just hangs. Damn it, you say, it was working fine on my PC. You go back to your source and try to figure out why that happened. After a lot of poking around/debugging/swearing, you notice that you call this simple property on a control and it never returns. Or sometimes, it returns, but doesn't update the UI correctly. You then read something about calling BeginInvoke. What's that, you wonder. This article will try to answer that. Note that this article will be dealing with the BeginInvoke method on the System.Windows.Forms.Control and not the BeginInvoke method that can be called on delegates to run them asynchronously.

A warning Control.BeginInvoke, which is what we have been discussing so far, works slightly differently from Delegate.BeginInvoke. Delegate.BeginInvoke grabs a threadpool thread and executes the passed delegate on that thread. Control.BeginInvoke does not use a threadpool thread, it does a PostMessage to the target window handle and returns. This is crucial because if it uses threads, then there is no guarantee to the order in which messages are posted and processed by the application. Also, unlike Delegate.BeginInvoke, Control.BeginInvoke doesn't require every call to BeginInvoke to be matched by an EndInvoke. Of course, if you are using the return value of the method and/or out or ref values, then you need to call it anyway.

29. Changing a WinForms Control on the 'UI' Thread from another Thread

this.BeginInvo...

30. Proper Threading in Winforms .NET

Illustrates a simple example of using the Invoke capabilities of Winforms

31. Towards Cleaner Code II, a C# GUI Invoke/Async Helper

An async helper class in C# with GUI Invoke capability, that greatly reduces the code required to invoke and track tasks that affect forms and controls.

Misc

32. Structs in C#

Explains differences between classes and structs, and how to use structs.

33. File Manager using C# and Multithreading

It helps to maintains files in directories with dynamically generated names using company's naming convention, versions and release

34. File Splitter Utility in C# - WinForms

Simple File Splitter / Joiner utility that demonstrates FCL and Winforms UI processing

35. Step by Step Threads

Step by step cross thread communication and thread-safe form control updates.