3 Replies Latest reply on Nov 4, 2008 8:09 AM by nmj

    Communicating between Flex and .NET

    flashphpdev
      I need to be able to setup communication between Flex3 and .NET. I have been reading about the following:

      - HTTP Services
      - Web Services
      - Remoting

      Based on what I have read I believe webServices will do what I need for my application. BUT.... I cannot find any information stating I can call the Flex client from .net as a request. Everything seems to be ( request -> response ) from Flex to .net. Can the ( request -> response ) cycle work both ways? If yes, can someone explain how to use an operation defined in SOAP to call actionscript. I think I am missing something here.

      Here is what I want to be able to do.

      - Flex app loads up and is running.
      - An .net based application changes state.
      - .net sends the information to the flex client
      - flex could send a response back to .net.

      So the concept is Flex Web Services backwards. Request's come from .net and responses go to flex.

      Alternate Option:
      Can I make a request from Flex to .net and then send a response later when the .net application changes state???
      - Are response's sent with a return statement. Or can I dispatchEvent's from .net?

      Thanks for you help.
      Dustin
        • 1. Re: Communicating between Flex and .NET
          bholli
          This may be slightly incorrect...

          if your web service's url is: http://localhost/FlexAsp/Service.asmx,

          and your c# webmethod is:
          [WebMethod]
          public string HelloWorld(string myName)
          { return "hello, " + myName; }

          then the following mxml code would call the function:

          <mx:Application xmlns:mx=" http://www.adobe.com/2006/mxml" layout="vertical">
          <mx:WebService wsdl=" http://localhost/FlexAsp/Service.aspx?WSDL" id="service" />
          <mx:TextInput id="myTextInput" />
          <mx:Text id="myTextOutput" text="{service.HelloWorld.lastResult}" />
          <mx:Button id="btnSend" click="this.service.HelloWorld.send(this.myTextInput.text)" />
          </mx:Application>

          Keep in mind that I have not tested any of this code..
          • 2. Re: Communicating between Flex and .NET
            flashphpdev Level 1
            Thank you for the response. Not exactly what I am looking for.

            The goal of a web service is to make a (request) from flex through a web service that flex & actionscript initialize. That request then hits the web server counterpart (asp, php, etc..) to be processed.. This is an operation call through the web service.

            What I am looking for is the concept ExternalInterface does.

            ASP calls flex through a web service setup by Flex. Now the first thing you will think here is ... How would ASP know that Flex has a webservice let alone communicate to it? Not sure..I want to know can it be done and how?

            I think the concept of web services is limiting since it is a 2 way communication cycle where the request only come from the web service initializer, in this case FLEX.

            I would like to have a site that uses a flex client for a small part of the enitre application. I want to be able to use asp to make updates to other parts of the site which in turn update a database. I want FLEX to know this update has occured and when by brocasting a call through a webservice. The reason I am content on web services for this .. is my flex app will use the service to update the data when states change in the flex app.

            It would suck to have to use ExternalInterface so ASP can make that one request to flex and then every other (request -> response) go through the web service.

            Why are Web Services one way??????????????????????????? I was under the impression it is this great feature, but never thought it would be limiting in this way.

            Dustin
            • 3. Re: Communicating between Flex and .NET
              nmj
              Dustin,
              The nature of a web service using the HTTP protocol is that it is totally client-side initiated, so your web server does not retain a live connection to the client in order to signal the changes. if you really want to use a web service, you will probably need to set up an instance of a timer class ( http://livedocs.adobe.com/flex/2/langref/flash/utils/Timer.html) in your Flex client to poll the server for a "last changed date/time" and when the server replies with a new value, then you should have the client pull the new data and update your client. The down side to this approach is that the clients will only get the update as quickly as their cycle time permits.
              I believe you have an option to use remoteObject instead which could keep an open connection between the client and server, but I have not tried it...yet. Both of these will have scalability issues if you have many users connected at the same time, but the architecture necessary to handle each approach will be different, so you should decide up front.