I have a mobile applciation thats interacts with a server. The mobile application should be allowed to do a http posting to the server.
The server should be able to handle the event and display out using a custom windows .net application on the server almost immediately based on event.
So what are the right ways to do it?
Is there any event handling that works on c#.net that can be applied on the above scenario?
So far i only thought of msmq event handling. The mobile app does a http post on the server, the server creates a msmq on the server side and the windows applications listens for the new msmq message.
If you must use HTTP post then you could write your own web server in C# and add handling for specific requests from your mobile device.
This project outlines how to create a web server in C#. Inside of the StartListen() function you can check for your target message instead of "GET". Alternatively you could use the functionality from this open source project: http://webserver.codeplex.com/ and hook the appropriate HTTPListener functionality.
The real thing to understand here is that the "web server" is really just a thread that is listening for a specific data stream on a socket. You could easily adapt simple socket send / receive code like this to implement your functionality.
Related
I have an application in WPF c# which will run on client machine. Another application (maybe some kind of service) on a particular server will be running all the time and will wait for any incoming message from the client app. As soon as the server receives a request from any of the client application, it triggers a command line process and also responds to the client about the staring info(whether it was successful or not) and as well as when the command line process is finished it again responds to the calling client application that it got finished.
I am new to in this area.
So my question is should I use normal windows service or Web service or WCF?(Some kind of link to a demo project will really help). Any other suggestion are also welcomed.
You did not mention if your clients will be outside of your firewall or with in the same intranet. We have intranet scenario, and we use WCF service that communicates with WPF based applications over the internal network. WCF provides Duplex feature which enables two-way client server communication using an easy to implement programming model. I recently wrote an article on this and it can give you a head start for the WCF way.
However, WCF does not have the best support for callbacks over the internet and you may have to look in to effectively using it in your case. But if it is intranet, then my suggestion is surely to go for the WCF way. Hope it helps.
Background
I have multiple servers that I currently connect to remotely to run a number of different commands/scripts to obtain information about the servers and/or applications running on the servers.
I'd like to automate running the commands/scripts (or the code contained in the scripts converted to C#/.NET) and have the server send alerts/notifications/messages to a client (basically a Windows Form) running on multiple workstations, but need some guidance.
For reference, I have limited experience creating Windows Services, but feel fairly confident in being able to create them on the server to handle to command/script automation, which I'm assuming would be the best way to go about handling the command/script automation on the server (since the commands/scripts would need to be run all the time or at set intervals).
Question
How can I connect multiple servers to multiple clients so that the server sends alerts/notifications/messages to the client when a command/script or even an event occurs on the server?
For instance, if an application on the server has a built-in command that can be run to determine the status of the application (up, down, limbo, etc.), I would like the Windows Form on the client to receive an alert from the server when the command returns "down" or "limbo" when it is run, presumably from a Windows Service. The alerts would be displayed on the Windows Form that would be setup basically as a dashboard for the servers that the client can connect to.
An even better outcome would be that the client runs as a background application and a notification appears similar to how Microsoft Outlook displays a notification when new email messages arrive (although these notifications would likely require user interaction to close instead of fading out like the Outlook notifications).
I would also like for the client to use a configuration file that has the connection information for the servers in it so that the servers being used can be changed quickly new servers are added or existing servers are decommissioned.
Research (so far)
I've read about WCF and duplex contracts, and how WCF can be hosted in Windows Services. From what I've read, this seems promising. However, I'm not quite sure how I would set this up so that the client can connect to a WCF service on multiple servers.
One thing that I'm concerned about with WCF is that in all of the WCF examples (which implement a calculator-type service) I've seen the client has to initiate the communication with the server in order to receive a message through a callback. In the calculator service examples, the client sends numbers to the service and the result is provided in the callback. I've also seen an asynchronous example, but in that example the client initiated a single, long running request and the callback returned a single response when it was finished processing.
And, just so I'm clear about bindings in WCF, it is possible to create and use bindings for multiple servers using a configuration file without having to use SvcUtil.exe to generate the code, correct? The reason I ask is because the servers that will be configured will likely be change for different users, so the client needs to be flexible when connecting to the services.
I've just now started looking at Sockets, but I'm not familiar enough with them to know if this would be the better option to achieve my objective.
Summary
I'm just looking for guidance, so if you can help direct me to some resources that will help me achieve my objective, I would appreciate it. I've searched extensively, but the majority of my searching either doesn't apply to my scenario, it is limited to a single server/client interaction, or it is limited to a single server with multiple clients.
Since I'm not sure what direction to go in, I don't have any code examples, although I have implemented the examples in the following Microsoft article: Windows Communication Foundation - Getting Started Tutorial
So you want to build a system of
multiple servers which execute commands on the computer they are running on
multiple clients which will receive the status of the commands executed on server or such information from the server
This would be my advice
Servers can be implemented as windows service. You will be able to administrate them easily this way using the services console or the scm. Checkout this link for a creating a simple C# service How do you write and use a Windows Service in C#?
Also, you can set the service to run as an in-built service user with different levels of permissions in addition to regular user accounts.
I have not used WCF, but usually clients connect to the server; this is a pretty common model, and hence all samples are such. Initiating connection from server is not a big deal (at least in a socket program), but just a bad model. You have to ask yourself, if no client is connected to your servers, how can they relay a status to the end user. You have to think clearly about the communication model. I would suggest a central repository of messages. It can be a file on a shared file system or a database or any such entity which can act as a data repository. This way all servers can convey there messages without caring if a client is connected or not. You can use Sockets to achieve what you want to do. Check the asychronous socket server sample from MSDN to understand how to do it.
Making the client run in the background and just have a notification area icon is also easy in c#. You can use NotifyIcon Class for that. This CodeProject article (Formless System Tray Application) demonstrates its usage. To show notification a la outlook style, you can refer to the following post: How to create form popup from from system tray on windows application (not web) with c#. Look at not only the accepted answer but other answers too; there are lot of useful links in it.
So far we have windows service talking over sockets, storing messages in a central repository and capable of handling multiple clients with toast style pops for client side notification.
You need a far richer client side GUI so the end users can take actions on the messages sent from the server. You can maintain a list of servers in app.config for the client that the client connects on startup. You should to provide a GUI for users to manage all servers and their connections.
Lat but not least, by building such a client server model, you are effectively building a security loophole in your systems. You should implement a good authorization mechanism. Checkout the following post: Authenticate user in WinForms (Nothing to do with ASP.Net)
EDIT:
You can also implement your server to accept "custom command" when you implement it as a service. This way, your client server communication will be standardized by using ServiceController to pass the command. This post might help: How to send a custom command to a .NET windows Service from .NET code?.
Don't get confused in the "command" terminology here. ServiceController issues standard commands to a service for start, stop, pause, resume and restart the service. These are the same items you see on the context menu when you right click a service in the services.msc snap-in. The same way a service can respond to custom commands. In your case the custom command maybe a request to execute a process.
Note that some mechanisms I have described are geared towards an intranet setup while others scale fine on both intranet and internet
I have Windows service written in C# that basically acts as a timer to fire an event. When the service fires I need to call a Angular.js controller passing variable(s) and receive a PDF file back as the response. I'm new to Angular so any help would be appreciated.
Angular lives on the client side in the web browser (well, typically anyway) so if you want to communicate to it from your C# service you need to find a way to send and receive information between your server (running the service) and the client browser.
How you can go about this depends on your project's needs, but for timed events you're probably best off using websockets to perform this communication. If you're working in C# you might want to check out SignalR for your backend.
I want to build a web-based irc client with JQuery. I know I need to open a socket to the irc server. What I'm wondering is, is it possible to open a socket purely from server-side C# code? Or would the nature of a web application prevent this and I would have to write a service to run on the host machine?
Thanks for any help :)
Yes, you should be able to make a socket connection from server-side ASP.NET code. On the other hand, given that you'd presumably want a persistent connection to the IRC server (rather than a new one on every request), you may want to write a separate service anyway - you don't want ASP.NET recycling to kick in and wipe all your context, for example.
Your ASP.NET code could then talk to your service to find out what had happened since the last request for that user, etc.
One simple approach would be to setup a singleton WCF service which acts as the bridge to IRC. jQuery AJAX calls against that service could then post messages that were input by the user, as well as retrieve messages sent by other users.
I have implement the chat with ASP.Net by using the SingnalR for duplex communication.
What I really done consist on the following steps.
1) ChatHub.cs
I have write down all the logic to connect with the IRC server and connect to the channels, receive different messages and notification from the IRC server. I then send these notifications to my ChatHub client by calling the javascript call backs from the ChatHub.cs
2) Client.aspx
Simple HTML page and it is using jquery to register the callbacks from the ChatHub.cs
3) IRCDotNet.dll
I have used this library to communicate with the IRC Server.
Hope, It will help somebody. Here is the link to download the IRCDotNet.dll
http://ircdotnet.codeplex.com/releases/view/50639
I am doing applications on .net remoting ,i write the code for
Client -----------> server
but
client <------------ server
i don't know how to do it(just like a chat),Please give suggestions and some samples to look up.
without any request from server i send messages from my client application
Try using MarshalByRefObject and events. This would allow the Server to respond back to the client.
Here is a sample on code project
Another Sample with Event CallBack