Develop Reference

C# Winform and ASP.Net and Xamarin

Right now, I'm in C# Winform and I would like to use my Windows Application with ASP.NET including with Xamarin. So, I need to know, what kind of program do people often use to make application run in all kind of devices (Computer + Web Browser + Smartphone)? And what should I use, WPF or UWP or which one?

This question is a bit broad/unclear, but you could consider porting your app to an ASP.NET frontend, and then load it with a wrapper on mobile phones and desktops.
Essentially create native apps that in turn load the ASP.NET web app. This is a quite common approach as it reduces development time.

If I understand you clearly, you want to make an ASP.NET Core application.
That is an webapp and if you use bootstrap it will scale on every device.
And because you use Core, you can host the webapp on every server (windows, linux etc.)

Can i use WCF Services to develop a Distributed System(as middleware)

i am new to visual studio, and i developing a distributed system with visual studio, i'm developing two applications
windows forum application c#
Web application asp.net
so i using WCF Services to make this system distributed, is is right?
in web application im using a WCF Services to Login and insert data and retrive data.

In your situation, i can say WCF would be fine. But in future if you are planning to support your application on devices like smartphones/tablets then Web API would be better choice.
But its totally depend on the situation. You will get more info on the following link:
http://www.dotnettricks.com/learn/webapi/difference-between-wcf-and-web-api-and-wcf-rest-and-web-service
Hope this will help you to choose appropriate option for your application.

Creating a server and site with ASP.NET

following my previous post about my game server, I've decided that I want to create a web-based server, and not a WPF one.
Currently, the server is a console application. I run the server, it has a TcpListener, and I interact with TcpClients, and the only real console-y thing I have, is a bunch of Console.WriteLines that I intend to get rid of. The server itself is part of a class library, which contains all the server logic, so that it'll be easy to wrap it in whatever platform I need.
Say I have a library with all my server-side logic, and I want the GUI of the server to be a web client, while still having a server that runs in the background and keeps the game running - How do I do that with ASP.NET?
Since all my code is C#, it's natural that I would pick ASP.NET, and use MVC with Razor, allowing me to use my original classes as data in the website.
I can handle the website part of the ASP.NET, but what I need advice with is how I create a server that acts like my previous one (runs in the background, has some sort of GUI, for input, commands and etc), and also has a website as the GUI.
Thanks in advance!
for reference, all my ConsoleApplication code is here, showing just how little the platform that runs the server has to do.
And regardless, this is the link to my game code, if anyone is interested. I'm always interested in opinions and constructive criticism!

This is an article about self hosting webapi and static files in a console application using Owin, no support for MVC. Asp.Net Core has a similar work flow (though it's not called Owin anymore), and MVC is available. Asp.Net Core apps are actually self hosted in a console application using Kestrel. When you host asp.net core in IIS all IIS does is act as a proxy.

Best Approach to communicate between a Windows forms application written in C# and Native Android App

so our company wrote an accounting app,in windows,using c# for a certain company that ordered an accounting application.
after a while,they requested an android app that can communicate with the server and request or send data from or to the database that the windows form application uses,which uses SQLExpress 2014.
note that : the application that runs on the android platform may need run on more than one client at any given time.
AND
the android app will be native.
my main question is this : whats the best technology to use?
do i HAVE to use web services ?

well to do that i have to install IIS on the windows client which is
all im trying to avoid,because i have a setup and the program has been
mass produced within the city so i cant just take back every
customer's product and add iis setup procedures to the setup...if u
know what i mean
Not true. Since WCF days, there's an in-process option called XXX self-host which is a tiny web server written in C# and started along with your process using code.
Currently your best web should be developing your Web services using OWIN/Katana self-host and implement your RESTful service running on a Windows service (did you know about TopShelf?).
Check this interesting MSDN article to learn more about self-hosting a Web API into a Windows Service using Topshelf.
TL;DR
Your best bet here would be creating a Windows service which might be installed along with the Windows application or in some customer's server machine and host this way your RESTful Web service using ASP.NET Web API.
This is easy to deploy and distribute, and your customer won't require an IIS installed to host web services.

Good way of communicating between web and desktop app

I want my web app (running in a browser) to, at some point, communicate (bidirectionally) with a desktop app (in Windows), the client has installed in its computer.
What's an elegant and modular and simple way of doing this (with Java and C#)?
Not much information will be passed between the web app and the desktop app. Just something like "I was here", "Pick this from this point", etc.

I solved that problem by using a database on the network.
All communications where made trough the database.
Website -> DB -> User logged in <- DB <- Desktop
However, if no trusted information needs to be shared, you could consider just posting and reading some http headers to a common website, or a simple log file.
Greetings

I suggest you to use the backend part of your webapp, assuming that your app is based on some backend services.
You have two options:
Your desktop apps use the same services of your web app. You must use a class that mimic a web-browser to give the data (curl, ie). If your web app is based on AJAX push ( APE Server i.e ) use library that is able to run some javascript
Use a REST protocol, with a JSON format in your backend services. It's easy to manage and is supported by many client-side languages (java/c#/python....)
Use a specialized endpoint only for your desktop app,for C#, you can use WCF, that allow you, in one of his forms bidirectional communications. For JAVA, there are WSDL, DWR
My preferred solution is to decouple the web app in a front-end side and a backend side, that expose the services as REST that are used by the web app via AJAX.
If I need true bidirectional communication with other desktop app, I'll create a separate service / endpoint for it. (APE , WCF, ..)

I see several options to achieve part of what you are asking:
Besically you expose the relevant parts of your apps (web and desktop) via some sort of API and use that for the communication - for example DB and/or WCF (SOAP/REST/whatever).
BEWARE:
If you are after some sort of direct/interactive communication between both apps on the same computer then this won't be possible - at least not without some security related issues.
The browser executes your web app in a sandbox which doesn't allow for direct communication between the web app and the desktop... there are technologies which can help circumvent that (ActiveX, signed Java applets, some Flash technology called AIR etc.)... or you could host some webbrowser/control in your desktop app which in turn runs the web app... BUT basically I would recommend against using any such measures...
IF you really want to go this route then please describe your environment and goal with much more detail.