I want my WP7 application to fetch data from the DB; so it sends the query as string, the server execute the query, then send the result back.
how can I do that?
whatever you can do for me I am so thankful to you, I appreciate, if you provide any sample code (I am using C#).
thank you,
Regards,
Lena
You can use web services (WCF, .asmx, REST, etc. - however you want to build them). However, you should not be sending your query across, that is very bad for security. You should just be passing in parameters to your web service functions.
I don't have sample code for it, but for any connected system (client application, mobile app, whatever) your two best choices (In my experience, and depending on needs) are publishing the data source as OData or using some more specific WCF (or other web-type service) service to handle pushing the data back and forth.
Then, to your phone app, the request is basically just a web call.
Related
I have currently built application in which I handle Products, Accounts, Orders, etc.
There are two databases one is a database which I created where I handle Users and Roles and some minor Application specific data. The other database is external and it is the one which holds all the data about Orders, Products and Accounts.
What I am trying to figure out is: how to build a server which runs parallel to the main application and handles all data manipulation with the external database.
Let's say a situation in which this would be helpful: There is an excel file which has to be created based on big amount of data and afterwards it has to be stored in the externalDB as certain type of format and sent as Email to someone. This will surely overload the main thread of the main application, hence we don't want that. Therefore, it would be a good idea to handle those kind of situations outside user's vision.
I am using ASP.NET MVC 5 and was curious what would be a good approach for this situation? I was thinking that I should make Console application, which is working as a service.
You would create a service architecture and have the services communicate with each other through controllers. These could push data back to the main application views, or the views could request data push from the services.
If you wanted to have jobs etc running on that server that send emails, you could easily just create SQL jobs or SSIS jobs or even custom service jobs that did that based on your criteria that are separate from the main view (where view is the main application that the user interacts with)
Services themselves could be configured with a light User Interface that you could call up on the server, perhaps in the service tray or through the Services component of Windows.
SOA architecture
https://www.cleverism.com/how-to-build-service-oriented-architecture-soa/
Micro Service architecture
http://microservices.io/patterns/microservices.html
Hope that helps. Good luck!
There are quite a few ways to do these kinds of things.
If your applications are for Android or iOS devices, it's common practice to have an external server running which handles intensive processing including managing your excel data, sending emails and database communication.
If your applications are cross-platform desktop applications or OS-specific desktop applications, you can still be able to use the external server, although certain other parts of the processing may be done on the client machine.
By using a web service to deal with database communication, it makes the applications more secure in regards to hard-coded database connection information, SMTP server credentials etc.
Using a RESTful web service will mean that you're adhering to the Hypertext Transfer Protocol (HTTP) which is great for exchanging data in the majority of cases.
Using a console application which acts as a TCP client server allows you to use the Transmission Control Protocol (TCP) to communicate in a different way. You're able to pass on data in a custom format if you wish. You'd be able to create a standard for communication which your applications will need to stick to.
The console application would do the same processing as the web service, however you would be in full control of logging requests, responses and data transfer.
We want to create apps that connects to our database (Sybase ADS, connectable via .NET) over the Internet. The clients will include a windows forms app and probably an android app for phones and devices.
I know C#. I'm new to Web apps and webservices so bear with me here.
I'm thinking maybe the best way is creating a webservice in C# to run on IIS that will interrogate the ADS database using ADO.net.
So the webservice will expose methods via WCF that can be consumed by the clients.
The clients then invoke the methods via WCF. Am I right in thinking WCF will return data in .net XML objects?
Also can .net Forms consume XML objects easily?
The apps would have bespoke restricted access using credentials.
How does this approach sound? Any performance or security issues to think about? The data is not exactly classified but I wouldn't want snoopers to be able to pick up phone numbers etc.
Can most security be sorted out by just going from http to https?
What about performance. Presumably slower than if the apps were just connected using ADO.net to ADS on the LAN. Does WCF use bufers for http requests?
E.g. can you can start reading the stream on the client before the whole http request has finished? I'm thinking for populating list boxes of large record nos. etc
I am looking for a way user can communicate between an ASP and Winform applications.
I am looking for something like soluto.com, I want to let the user send commands to other computers via Website. So let's say the user signed up for 10 computers, which is registered on the mvc app. User can select all the 10 computer and send a "Do this task" with a click of a button.
I am thinking something like, Winform will create a httplisten server. Everytime winform is open, it will send a "I am online" post to mvc, along with IP:Port. The server will send a request to that ip:port when required.
That approach seems very unsecure though, having an open port, configuring firewall and etc, seems like a overkill.
I was wondering if there way any other way of accomplishing this.
Thank you for the help.
P.S. Before you claim this is a stupid idea, Piriform is doing something like this also. Take a look at Agomo.com
Use SingalR with properly architected web and windows applications (e.g. MVP, MVC, etc.)
SignalR with window client (WPF)
Console App & SignalR
Create a WCF service within the WinForm application, specify endpoint(s) (and secure the endpoint appropriately), and connect to said endpoints from your ASP.NET application the same way you would also connect to a WCF service.
Why don't you just have the Winforms app use a standard HttpClient or WebRequest to periodically poll the service (maybe every 5 seconds or so) and ask if there if there are any tasks that need to be performed?
Unless you need realtime, low-latency, high performance communication then this is the easiest way to solve your problem with minimal to zero client side setup or security configuration.
The way I would do it is implement it like a stack in a data persistence layer. So each client could have rows in a table that are added when a task is queued. When the clients sends an HTTP GET request to the MVC server it will return the an array of tasks for that client and you could have it either delete them from the database right away or wait for the client to send a HTTP command later to indicate which tasks it completed.
You could represent tasks as a simple data object with a few properties, or just a string or int that you can lookup on the client in some way to invoke the appropriate code.
For reasonable security each client just needs to be given a unique key like a GUID or equivalent that it can later send to the server to validate its identity. This is also known as a cookie, secret, or API key.
I'm about to start to develop and application in C# but I realized that I haven't the enough knowledge to develop it yet :S.
The thing's that I need to find out a way to let the Web server comunicate with my application, i.e., in short, is there a way to let the web server (not the Client which is the trivial case) send a messege to a Client application?
I know that I way to solve it's to make Client applications periodically send messages to the web server but that's not what I want 'cause polling generates overhead
Sorry about my english! I'm not a native speaker.
Thanks in advance!
Generally this type of interaction is achieved with Comet or WebSockets - I'm not sure how your app will be communicating with the server, but I would bet you can do what you're trying to do using one of those.
You could implement a WCF service in your client that could listen for a connection from the server (or anything else). The server can communicate with the client as easy as calling the API.
Getting started with WCF is really easy using the wizards in VS.
Here is a link that talks about using WCF with ASP, but it can be used outside of asp as well.
It seems like you meant "push" messaging, the challenge around this is for the server to keep track of the lost of clients and manage who should recieve which message.
If you want to get it done with minimal overhead you can check out the Amazon Simple Notification Service.
SNS is a cloud-based messaging and notification service hosted and managed for you, SNS is based on a topic/subscriber model and you set it up via a few simple API calls, it is metered but quite inexpensive for the most part.
edit: For C# Libraries and frameworks to do it yourself, I am not an expert in the C# world so I think other answerers will know it better.
Disclosure: I work at amazon so I am naturally inclined to like their product
So I'm working on a project for my internship and have hit a bit of a brick wall. Unfortunately, the only people I know who are qualified to help me at the office are on vacation at the moment, and Google has been unfortunately unhelpful (or my search skills inadequate), so I thought I'd ask here.
The project is basically to make a server to mimic one that the company (which makes phone apps) already has. What I need to do is have one of their apps send a request to my server (I will have to modify the app to do this, but don't know how), and have my server reply with an XML response that the app already knows how to process. (The main purpose is so that we can see how the app responds when the real server sends it an error by simulating it on my server.)
Now, I already have a few sample HTTP requests and their associated XML responses handy, taken from simulations with the app and the real server. The app is written in C#, and currently sends HTTP web requests to the real server's online location, which responds to these HTTP web requests with XML. My server, however, will not have an online location, so the app will have to be modified to work with sockets on a local host.
My questions:
1) My boss said to create an XML file to associate certain requests with certain XML responses, but I have no idea what he means or how to do this. (He said it could also be done with a .ini file.) Does anyone know?
2) Once I have this XML file that can make these associations, how can I incorporate it into my server so that my server can check the request it received against its table of valid requests and figure out which response to send back?
3) How can one modify the app from using HTTP web requests and responses to using sockets?
If you have any questions/clarifications that you need in order to better answer this, please don't hesitate to ask me.
Thanks!
What you're describing is a web service. Unfortunately, his advice to change a setting in an .ini file make it sound like they have a proprietary system for doing this, rather than using a standard ASMX (which requires IIS) or WCF (which can either run in IIS or as a standalone service, which it sounds like is what you'd want) service.
Without more information about what they're using, I don't know that you'll be able to get much help here.
In response to question #3:
HTTP is a protocol that already runs on a specific socket (normally using port 80).
An internet socket is an endpoint that is used to transport data between processes. If you want to run your own protocol, you will need to create a new socket (with TCP or UDP) on a specific port.
This will however require you to create your own client and server in order to exchange data between them.
To get started, here is a very simple client-server example in C# using a custom socket.
Good luck!
Ask your boss if this client communicates with soap, if so then just go to MSDN and find tutorials on implementing an ASMX webservice, follow the tutorial through and you'll have a shell to start with.
First I'd like to say that it sounds like you have some unclear requirements that you should probably clarify with your boss. If you're not exactly sure what he means you should find out because nothing sucks more than having to support someone's creative interpretation of requirements.
1) It sounds like your boss just wants a way to easily change associations for testing without having to rebuild the app so he's asking you to store those associations in an xml/ini file that can easily be modified. In c# you can easily go between XML and DataSet objects so this should be trivial. I would create the data structure in a DataSet first and then use the GetXml method of the DataSet to output the xml format.
2) In .NET you can store objects in Cache and create a Cache Dependency that is a file association. Thus whenever the file is modified the Cache is purged. Whenever your program handles a request it pulls the object from Cache, if the object isn't in Cache then you have a condition block rebuild it from the xml/ini file on disk. I would have that condition block call out to a function that then loads the above mentioned xml format into a dataset that is then stored in the Cache with a Cache Dependency.
3) If you are trying to test an applications i/o, modifying it to use a different transport layer sounds like a bad idea. If the app currently works over HTTP to send requests then just route the HTTP request. I would suspect that the app probably has a configuration somewhere defining the path of the webservice it currently calls out to, once you know what that path is you can either change it, or if that's not possible setup a DNS rule on the server running the app to route it to the location of your application. On windows this is as simple as adding a line to the hosts file.