Display Messages after getting response from WCF

Question

I am building a WCF Application for Push notification where user have to first subscribe himself and after subscribe the client get response from WCF.

i use wsDualHttpBinding as binding and callback in WCF.

I don't want to call recursive function from client. I use timer in WCF and WCF throw messages when any update is happen in database. My WCF is ready but unable to display messages on client side.

Now my question is how to Display messages when client get response from WCF.

My client side code on aspx.cs is:

public void SendResult(string message)//I got message = "Test String"
{
   Response.Write(message);// it throw error "Response is not available in this context."
// I also use this code 

HttpContext.Current.Response.Write(message); // but it also give error "Object reference not set to an instance of an object."

}

This is a very critical question and i have to just display the message

Any help will be appreciate.

Edit 1

Service Method call

  protected void Page_Load(object sender, EventArgs e)
  {
        SocialProfilesService.SocialClient client = 
               new SocialProfilesService.SocialClient(new InstanceContext(this)); 
        client.Subscribe(userid)
  }

Edit 2

I also tried

 SynchronizationContext uiSyncContext;
 uiSyncContext = SynchronizationContext.Current;
 public void SendResult(string message)//I got message = "Test String"
 {
   SendOrPostCallback callback = delegate(object state)
    {
        Response.Write(message);
    };
    uiSyncContext.Post(callback, message);
 }

but it also gives me the error "Object reference not set to an instance of an object." Wht to do

I already saw this article. i prepare my service according to this article. but noting find suitable to display messages on the web. — ankit Gupta, Feb 11 '13 at 06:26
Point is are you able to get anything or some kind of error ? How you made sure that your subscriber is working fine . I am not able to understand here the problem is with the service or just displaying a message ? — Tabish Sarwar, Feb 11 '13 at 06:35
@Tabish: The serivce is working fine. The problem is to just display the messages on the web. i am getting the response also but can't show it. — ankit Gupta, Feb 11 '13 at 06:39
@TabishSarwar: Sorry!.This is also i used before but not working in my situation. — ankit Gupta, Feb 11 '13 at 06:56
Why are you using void if you want to return a message? you can use stream that will be returned. — Dev, Feb 11 '13 at 07:01
@Dev: we have to just display the data. not to return anything. — ankit Gupta, Feb 11 '13 at 07:06
@ankitGupta whatever ! if you won't return it, how will it be displayed to client? — Dev, Feb 11 '13 at 07:08
@Dev: this function is called by WCF and i don't need to be return type. i take parameters and i want to just display the message. — ankit Gupta, Feb 11 '13 at 07:13
@ankitGupta You mean to say that you want to display the message that come from client to the server page? — Dev, Feb 11 '13 at 07:16
@Dev: Yes Dev, now u got it. my service is working fine and it push the messages to the client succesfully. now how to display it. — ankit Gupta, Feb 11 '13 at 07:19
@ankitGupta Its quite a difficult task, you can store the message from client in the database, while client call the service and then on page load simply display it. Direct showing message in Page Load is difficult. — Dev, Feb 11 '13 at 07:52

Tabish Sarwar · Answer 1 · 2013-02-11T06:50:54.807

You should look at this article. This should help. It gives a nice simple example of subscribing and pushing updates.

Article

As per our discussion. It seems your service is working fine. I am assuming that you are calling SendResult appropriately and passing in the message. Here is another thing you can try... This is java script alert from Asp.net

    Page.RegisterStartupScript("startScript", "<script language=JavaScript>Message("+message+" );</script>");

    Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "testmsg", "<script>alert('your message goes here');</script>");

Display Messages after getting response from WCF

Edit 1

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1 Answers1