C# Client-Server application - c#

I need to write a client-server application. First of all, I'm going to write an application server. Also my app server should connect to database(MS Sql Server) and give data from it to client app. So, as I know, I should use WCF. Is it a good idea? Maybe I need to take a look for something else?

Lets start with client-server architecture.
Assuming you have finalized that you need client and server, but have you decided carefully the architecture? I mean what type of server and what type of client you are going to create?
Let's see the options here:
Server
1. What type of hosting you are going to use?
2. What type and how much load your server needs to handle?
Client
1. Type of consumer of your service
2. Do client need to be deployed on local machine or it should be web based?
There are obviously more concerns than above. Initial design should be as flexible as possible.
So, now lets look at some solutions regarding architecture.
Server:
1. Application Hosted WCF server: Each time you need to manage the server lifecycle. Also, this is not scalable. So if you are looking for scalable architecture, you need to look more.
2. IIS hosted WCF server: This might be a good idea along with some architecture concerns as per your need.
3. Web Method: Obviously this came after WCF, but WCF is still in its place. So the main difference is at What is the difference between an asp.net web method and a wcf service?
Now Client:
1. ASP.NET: This will enable to use a single client app for every platform obviously because of HTML
2. WPF/WinForms: This is going to bit tricky to use as client as you need to deploy the client app on user machine and here comes the data security problem. In former you can directly use SSL or some other way to send data to browser. While in this if you are not using WCF with HTTPS and there are some proprietary data going over wires, it may be concerns.
If you are looking for cross platform usage of your server you can use HTML.
Conclusion:
You can use Server as WCF hosted service (either in IIS or in self contained application) and client as ASP.NET.
-----------------------------If it is not big enough requirement then you can use ASP.NET as server and then browser as client (No need to create client).----------------------------
You can create server either as WCF as web methods and deploy the client on user machine.
----------------------------
WCF is nice enough and it can handle your proprietary data types as well.

WCF is a nice thing, but i would use ASP.Net Self-Hosted Web-API. It's more modern. And you have a full rest interface, which is much more popular.
Here is a comparison: WCF and ASP.NET Web API
Here is a good starting point: Self-Host ASP.NET Web API 1 (C#)

Related

How to host a WCF service

I am trying to create a chat application in WCF.
I've created the client and the service on a localhost using httpBinding,
this is the service endpoint:
http://localhost:9999/ProductService
Now, I really don't know how to make the program run 'globaly' and not on a localhost.
Is there anyway to host the server on my pc? or run the application serverless using p2p communications?
Thanks anyway for your Time
You can set up at publicly accessible web server on your own computer, but it's definitely not recommended for any production purposes, unless you have a good understanding of this and have a internet-connection that allows for it, both technically and legally.
You should probably get external web hosting for this instead.
But if you really want to do this, you can install IIS to host the service.
As a side note, I don't think WCF is the optimal route to take for this anymore. Maybee you should check out SignalR and/or WebSockets instead. And ASP.NET Core WebAPI. It's not really anything wrong with WCF, but for new projects I wouldn't recommend it.

WCF or Web API for windows form application [duplicate]

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I've spent a few months trying to grasp the concepts behind WCF and recently I've developed my first WCF service application.
I've struggled quite a bit to understand all the settings in the config file.
I am not convinced about the environment but it seems that you can do amazing stuff with it.
The other day I've found out that Microsoft has come out with a new thing called ASP.NET Web API.
For what I can read it's a RESTful framework, very easy to use and implement.
Now, I am trying to figure out what are the main differences between the 2 frameworks and if I should try and convert my old WCF service application with the new API.
Could someone, please, help me to understand the differences and usage of each?
For us, WCF is used for SOAP and Web API for REST. I wish Web API supported SOAP too. We are not using advanced features of WCF. Here is comparison from MSDN:
The new ASP.NET Web API is a continuation of the previous WCF Web API project (although some of the concepts have changed).
WCF was originally created to enable SOAP-based services. For simpler RESTful or RPCish services (think clients like jQuery) ASP.NET Web API should be good choice.
ASP.net Web API is all about HTTP and REST based GET,POST,PUT,DELETE with well know ASP.net MVC style of programming and JSON returnable; web API is for all the light weight process and pure HTTP based components. For one to go ahead with WCF even for simple or simplest single web service it will bring all the extra baggage. For light weight simple service for ajax or dynamic calls always WebApi just solves the need. This neatly complements or helps in parallel to the ASP.net MVC.
Check out the podcast : Hanselminutes Podcast 264 - This is not your father's WCF - All about the WebAPI with Glenn Block by Scott Hanselman for more information.
In the scenarios listed below you should go for WCF:
If you need to send data on protocols like TCP, MSMQ or MIME
If the consuming client just knows how to consume SOAP messages
WEB API is a framework for developing RESTful/HTTP services.
There are so many clients that do not understand SOAP like Browsers, HTML5, in those cases WEB APIs are a good choice.
HTTP services header specifies how to secure service, how to cache the information, type of the message body and HTTP body can specify any type of content like HTML not just XML as SOAP services.
Since using both till now, I have found many differences between WCF and Web API. Both technology stacks are suited well to different scenarios, so it is not possible to say which is better, this depends on configuration and scenario.
Properties ASP.Net Web API WCF
--------------------------------------------------------------------------------------------------
End point (mainly) Http based SOAP based
Service Type Front End Back-end
Support caching, compression, versioning No
Framework ASP.net WCF
Orientation Resource Oriented Service Oriented
Transports http http, tcp, MSMQ, Named pipe
Message pattern Request reply request Reply, one way, duplex
Configuration overhead Less Much
Security lesser than WCF (web standard security) Very high (WS-I standard)
Hosting IIS IIS, Windows Service, Self hosting
Performance Fast A bit slower than Web API
In use from .NET 4.0 .NET 3.5
Note: The data is not only my view, it is also collected from other official websites.
WCF will give you so much of out the box, it's not even comparable to anything. Unless you want to do on your own implementation of (to name a few) authentication, authorization, encryption, queuing, throttling, reliable messaging, logging, sessions and so on. WCF is not [only] web services; WCF is a development platform for SOA.
Why I'm answering:
I took huge amount of time to understand the difference between these two technologies. I'll put all those points here that I think "If I had these points at the time when I was wondering around in search of this answer, then I have decided very earlier in selecting my required technology."
Source of Information:
Microsoft® Visual Studio® 2015 Unleashed
ISBN-13: 978-0-672-33736-9 ISBN-10: 0-672-33736-3
Why ASP.NET Web API and WCF:
Before comparing the technologies of ASP.NET Web API and WCF, it is important to understand there are actually two styles/standards for creating web services: REST (Representational State Transfer) and SOAP/WSDL. The SOAP/WSDL was the original standard on which web services were built. However, it was difficult to use and had bulky message formats (like XML) that degraded performance. REST-based services quickly became the alternative. They are easier to write because they leverage the basic constructs of HTTP (GET, POST, PUT, DELETE) and typically use smaller message formats (like JSON). As a result, REST-based HTTP services are now the standard for writing services that strictly target the Web.
Let's define purpose of ASP.NET Web API
ASP.NET Web API is Microsoft’s technology for developing REST-based HTTP web services. (It long ago replaced Microsoft’s ASMX, which was based on SOAP/WSDL.) The Web API makes it easy to write robust services based on HTTP protocols that all browsers and native devices understand. This enables you to create services to support your application and call them from other web applications, tablets, mobile phones, PCs, and gaming consoles. The majority of applications written today to leverage the ever present Web connection use HTTP services in some way.
Let's now define purpose of WCF:
Communicating across the Internet is not always the most efficient means. For example, if both the client and the service exist on the same technology (or even the same machine), they can often negotiate a more efficient means to communicate (such as TCP/IP). Service developers found themselves making the same choices they were trying to avoid. They now would have to choose between creating efficient internal services and being able to have the broad access found over the Internet. And, if they had to support both, they might have to create multiple versions of their service or at least separate proxies for accessing their service. This is the problem Microsoft solved with WCF.
With WCF, you can create your service without concern for boundaries. You can then let WCF worry about running your service in the most efficient way, depending on the calling client. To manage this task, WCF uses the concept of endpoints. Your service might have multiple endpoints (configured at design time or after deployment). Each endpoint indicates how the service might support a calling client: over the Web, via remoting, through Microsoft Message Queuing (MSMQ), and more. WCF enables you to focus on creating your service functionality. It worries about how to most efficiently speak with calling clients. In this way, a single WCF service can efficiently support many different client types.
Example of WCF:
Consider the example:
The customer data is shared among the applications. Each application might be written on a different platform, and it might exist in a different location. You can extract the customer interface into a WCF service that provides common access to shared customer data. This centralizes the data, reduces duplication, eliminates synchronization, and simplifies management. In addition, by using WCF, you can configure the service endpoints to work in the way that makes sense to the calling client. Figure shows the example from before with centralized access of customer data in a WCF service.
Conclusion:
i) When to choose Web API:
There is no denying that REST-based HTTP services like those created using ASP.NET Web API have become the standard for building web services. These services offer an easy, straightforward approach for web developers building services. Web developers understand HTTP GET and POST and thus adapt well to these types of services. Therefore, if you are writing services strictly targeted to HTTP, ASP.NET Web API is the logical choice.
ii) When to choose WCF:
The WCF technology is useful when you need to support multiple service endpoints based on different protocols and message formats. Products like Microsoft BizTalk leverage WCF for creating robust services that can be used over the Web as well via different machine-to-machine configurations.If, however, you do need to write an application that communicates over TCP/IP when connected to the local network and works over HTTP when outside the network, WCF is your answer.
Be Warned:
Web developers often view WCF as more difficult and complex to develop against. Therefore, if you do not foresee the need for multiprotocol services, you would likely stick with ASP.NET Web API.
There is a comparison on MSDN about this
WCF and ASP.NET Web API
For me, the choice was about Who the clients are, and where are they located?
Within the company Network and .NET based clients : Use WCF with TCP binding (Fast communication than HTTP)
Outside the company Network, and use diverse technologies like PHP, Python etc: Use Web API with REST
Business speaking, WebApi lacks of a WSDL, so the developers should document all manually. And if, for example, the WebApi operation returns a list of objects then, the client should creates the objects manually, i.e. WebAPI is really prone to errors of definitions.
The pro of Webapi is its more lightweight than WCF.
Regarding the statement "WebApi lacks of WSDL" there are several ways to generate Rest client. One popular approach is Swagger UI / (Swashbukkle Nuget). This gives a rich interface to understand the REST end point's input and output schema and online tool to test the end points.
JSON LD (Json Linked Documents) is another emerging standard which will further improve the JSON based REST developer experience by exposing the JSON schema with better semantics.
With wcf we can configure and expose the same service support for multiple endpoints like tcp, http.if you want your service to be only http based then it will be better to go with web API. Web API has very less configuration when compared to wcf and is bit faster than wcf. Wcf also supports restful services. If you have limitation of .Net framework 3.5 then your option is wcf.

Sending data via WCF

I was wondering how you can send data from the client to the host. Currently I have 2 projects and one WCF library. One of the projects is a pump which is the client and I want it to be able to send data to the host? Although I may have a misunderstanding of how WCF works. I was wondering if anyone could point me in the right direction. The problem requires me to use WCF. I want to be able to pass a list of strings to the host.
WCF can send data over many different transport protocols like MSMQ and http. It also enables message security, distributed transactions and other more complex features of a distributed system.
You need to create a WCF service, which is available as a template in Visual Studio. The server should be hosted as a stand alone program os as a web application in IIS.
Afterwards you need to create a client, that can communicate with the server.
WCF is however a large and complicated framework and you should not expect to be able to just scratch the surface and build a system. You need some googling and could possibly start with MS own tutorials.
If you need real useful answers you should be more specific about your program and the client and server operations as well as the deployment scenario.
As faester already said, WCF is a large framework and you can not make a good application by just copy-pasting the code into your project.
You should really read into the matter and then create your programming masterpiece.
faester gave you a link, but it's for basic WCF client-server communication.
Here are some good links on sending and receiving data via WCF:
Data transfer and architectural overwiev
Using the Message class
For a simpler, task-oriented view of how to send and receive data, see:
Specifying Data Transfer in Service Contracts
I hope that this will help you and the people yet to come to this question.

how to create a c# app to listen for xmls and reply in xml

I know that you can create web services in .net and have them run on iis. I'd like to make something that doesn't rely on iis as the webserver I'm using runs apache.
The eventual app should listen for incoming xml documents and repy in the form of an xml document, the client application will be running Javascript and sending xmls via http post requests. Is this something that SOAP handles?
All the guides and tutorials seem to follow the microsoft way, all hosted on servers running iis... is there a way around this?
As you can tell I'm quite confused as how to start.
I would strongly advise against implementing your own web service hosting platform - this really isn't a trivial thing to implement, especially if you want to be passing proper web service messages between your servers.
One option that would allow you to utilize WCF and Microsoft's baked in web service functionality is hosting WCF as a standalone service. In this model, you aren't using IIS to host the web service - you trade off some monitoring and logging functionality baked into IIS but it doesn't require IIS be installed.
Here's an article on WCF hosting options - http://msdn.microsoft.com/en-us/library/bb332338.aspx

What is the difference between the Visual Studio Options: ASP.NET Web Service and WCF Service

I see that there are two options that I know can be used in web services... WCF obviously, and ASP.NET Web Services. What's the difference? I just started picking up WCF recently and had a little exposure to web services in the past, but I'm certainly not an expert.
it is quite easy to know the differences.
ASP.NET Web Method is called ASMX [because of the file extension] (check 4GuysFromRolla about this, they have a good tutorial)
This technology makes you expose methods as a Web Service so you can connect it (to the WS) from everywhere and use it (the methods). But... you can't protect the data between server and client, like, you can send big files in a clear mode, etc...
[Note] you can protect the access to the web service using certificates, but it is a pain and quite complicated, normally in ASMX we use username / passsword to give access to a method (once again... in plain text!)
In WCF, you are in the different world about Web Services, and this is the best technology in .NET (so far) to expose Services (can you see the difference... Services! not Web Services), WCF does not need IIS to run, it can run as a System Service on the server, using a console ambient (like command line), in TCP/IP mode, etc, so we say that WCF is a Service, not a Web Service. Remember ASMX need IIS to run and will only run hosted in a Web Server.
With WCF you can use SSL to encrypt the communication (to do that in ASMX you need to use WSE - Web Services Enhancements) and it is quite easy to implement it, you can send big files and securely (to do that in ASMX you need to use MTOM - Message Transmission Optimization Mechanism).
you can set the transmission preferences just changing one line of code, or even, if you prefer, change the XML configuration file, the security is much higher, etc, etc :)
hope you get a better general overview with this, but there is much more.
bottom line: to expose Web Services that you do not need to protect, you can use ASMX, no problem at all, but if you need to protect the communication somehow, do it in WCF!
link: you can read here some performance comparative between the 2 services
ASP.NET web services was Microsoft's first attempt at web services.
WCF replaces ASP.NET web servies and .NET remoting. WCF provides a common programming model that enables you to do what the two older technologies where capable of and much more including support for a wide range of protocols and security models.
Go with WCF if you have the choice.
ASP.NET webservices is OKAY - but it's limited to HTTP hosted in IIS only, and has other problems.
WCF supports way more transport protocols (HTTP in various ways, TCP, MSMQ and more), has a lot richer security model (credentials, federated security), and offer options for hosting - self-hosting in a Windows app or service, in IIS or WAS and more.
In short: if you're starting now - go learn WCF by all means !
Marc

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