I have an ASP.NET Core MVC application, that i want to connect it to POS ( Point of sale) device, and send payable price to pos and then pos send back me the result.
I want to run these operations on client system. how can i send data to ports of client system?
Before I had the same problem. your web application can't communicate with the port directly.
To do that you have to do the following :
1-Create a windows service project
2-Host a web Api in windows service (Web API Self-Hosting Using Windows Service)
That way your web application can call web api hosted in windows service, because web api is listening to the incoming requests. in web api, you can communicate with your desired port directly and send the result to the client.
Finally, to use this feature in your web application you have to prepare a batch file(it runs your windows service) of your windows service project and put it in the download section of your website.
if any user wants to use POS( Point of sale) device have to install the bat file
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There is a server application (ASP.NET Core (gRPC service)) and a client application running on another PC (WPF).
One of the functions of the gRPC service is to send screenshots to the client application, but it has to be run as a Windows service, so I can't get screenshots directly from the service to the client application.
Question: how to implement an "agent" application running on a remote computer where the service is, but in a user session to get screenshots through it and then pass them to the client?
As I understand it is possible to do it with the help of IPC, but I can't understand the details of implementation, how can I call from gRPC service to the agent to make a screenshot, return the result (as an array of bytes) to the service and it sends it to the client...
I am creating a web app. I want to create a listening service (TCP) that listens continuously and updates web page according to that.
A Windows service or a WCF service?
At the end I just want a background service that listens on a socket continuously and update data in database. and when database is updated I will use signal r to show that in my page.
Right now I am trying with WCF but I am wondering if it can be done with Windows service also. And right now this application will work on LAN. But in the future, it can also be in the cloud.
First of all, it is important to understand that a Windows service and a WCF service are not the same.
A Windows service is a specialized executable that runs in the background on Windows.
A WCF service is a specialized piece of code that exposes some functionality through a well-defined endpoint. It does not run on its own, but instead must be hosted by some parent process, like IIS, a desktop application, or even a Windows service.
In thinking about the problem you've described, I suppose the most fundamental question to ask is whether or not you have control over the data that will be received via the TCP connection. WCF is built on the notion of the ABCs (Address, Binding, and Contract), all of which have to match in order to facilitate data exchange between WCF endpoints. For example, if you wish to expose a WCF endpoint via IIS that accepts TCP connections from some remote WCF endpoint, the remote WCF endpoint needs to send data to your IIS-hosted WCF endpoint using the agreed-upon data contract. Absent that, WCF will not work. So, if you cannot define the data contract to be used between WCF endpoints, then you'll need to find another option. An option that will work is to open a TCP listener within a Windows service, process the data as it is received, update your database, and listen for more data.
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By way of example, I work on a project that has a front-end desktop application that communicates with a back-end Windows service. We build both the application and the Windows service, so we have full control over the data exchange between the two processes. At one point in time, we used WCF as the mechanism for data exchange. The Windows service would host a WCF service that exposed a NetNamedPipeBinding, which we later on changed to NetTcpBinding to get around some system administration issues. The application would then create its own endpoint to communicate with the WCF service being hosted within the Windows service.
This worked fine.
As our system got more mature, we needed to start sending more and more information from the Windows service to the application. If I recall correctly, I believe we experimented with streaming within WCF and concluded that the overhead was not something we could tolerate. So, we used WCF to exchange commands and status information between the application and the Windows service, but we simultaneously used a TCP socket connection to stream the data from the Windows service to the application.
This worked fine.
When we got a chance to update the Windows service software, we decided that it would be better to have a single communication mechanism between the Windows service and the application. So, we replaced WCF altogether with a TCP socket connection that uses a homegrown messaging protocol to exchange information in both directions - application to Windows service and Windows service to application.
This works fine and is the approach we've used for a couple of years now.
HTH
I created localhost website in asp.net in Visual Studio and i added there a MSSQL connection.
My problem is that I created an app for windows phone 8 but i dont know how to connect this app with database which is on this website.
Can you help me with this?
First of all: your Windows Phone app can't connect to a SQL Server database, so you'll have to create an API.
Since you're using ASP.NET, I suggest to have a look at Web API. In short: you'll have several URL endpoints which return json/xml to your Windows Phone app. It's your job to query the database and return a single item/list of items in the controller of that URL endpoint (this sentence will make sense if you read into creating a Web API).
Next task is connecting to this API. Normally you would host it on a public url, so your phone device can connect to it (a phone doesn't know about your pc's localhost). If you want to use localhost with the emulator for testing, you'll have to execute the tasks mentioned in the quote below as this doesn't work out of the box.
When you create a WCF web service in Visual Studio, by default the
service is hosted in IIS Express and only accepts connections at
http://localhost/. Apps that target Windows Phone OS 7.1 can connect
to the development computer as localhost because the Windows Phone 7.1
emulator uses the network connection of the development computer. The
Windows Phone 8 Emulator, however, configures itself as a separate
device on the network. As a result, an app running on the Windows
Phone 8 Emulator can’t connect to the development computer as
localhost. Before you can connect successfully from the emulator to
the local web service, you have to make two changes:
You have to configure the local web service and web server to accept connections from other devices on the network.
You have to configure the service reference in the Windows Phone app to connect to the service by using the IP address of the development
computer on which the service is running.
Source: https://msdn.microsoft.com/en-us/library/windows/apps/jj684580(v=vs.105).aspx
I need to make an application where a mobile web app can connect to a local web service in a LAN. For example, several locations are running this web service on their own local server. When someone with the mobile app comes into the location they can open it up and it will somehow be able to connect to that local webservice through WiFi. The mobile app won't know the IP of that webservice ahead of time. Any thought on how to go about this? This will be a .NET webservice and HTML5 app but I don't think that matters.
As mentioned in the comments you will probably have to make it configurable by the user as the will ultimately need the address of the server.
There is however another approach that you can take. Develop a small multicast/udp service that broadcasts the web service address every 10-30 seconds. In your android application register a broadcast receiver that responds to the network connectivity status and runs in the background.
This service on the Android service will pick up the address from the UDP broadcasts and then configure the application.
I have a web application and on that application i update a sql database ...what i want is that when i update the database from the web application a notification will be sent to any one openening my application or a pop up appears to them on their desktop informing them that the database is updated to check all this will be in an intranet.
I'm using ASP.Net and I'm the admin for all the PCs in the network and the server.
Does anyone knows how i can do this ?
Build a desktop application that polls the database regularly or better write a HTTP/REST service where desktop application poll frequently.
What you need is a WCF duplex service your website and your windows clients connect to. With such a service you can use callback methods to inform your windows clients through the service. But be aware that this is normally an intranet and not an internet scenario because such an wcf binding has problems with internet infrastructure (Proxies, Firewalls, ...)