I want to send data from WCF to my desktop application while executing a service method.
The WCF service is hosted in windows service.
For example: In my service I am counting from 1 to 100 and when I am hitting 10,20,30 etc I want to set that value on my textbox.
This may be done using duplex channels services:
http://msdn.microsoft.com/en-us/library/ms731064.aspx
Be careful however : this will not work if the server can't reach the client : for example if you are behind a proxy.
I've simpy passed that with get/set like below: (Maybe someone will search smthing similar in future)
public class CallbackHandler : WCFService.IWCFServiceCallback
{
public ListBox LtBox { get; set; }
public void Message(string result)
{
LtBox.Items.Add(result);
}
}
InstanceContext instanceContext = new InstanceContext(new CallbackHandler() { LtBox=this.ltBox });
Where ltBox is my Listbox in desktop application.
Thanks all for help.
Related
I am developing a small instant messaging application that makes use of few DomainServices on the server side. Trying to access the domain service URL, I encounter the following error:
"ContractDescription 'AppInitService' has zero operations; a contract must have at least one operation".
The domain service Url is this one:
http://givemeword.net/chat/Services/IM-Chat-UI-Web-DomainServices-AppInitService.svc
You can find the domain service class below:
namespace Chat.UI.Web.DomainServices
{
[EnableClientAccess()]
public class AppInitService : DomainService
{
private System.Security.Principal.IPrincipal _user;
private readonly Chat.UI.Web.Services.AppInitService _appInitService;
public AppInitService()
{
_appInitService = new Chat.UI.Web.Services.AppInitService();
}
public InitUserSettingsDTO InitUserSettings(Guid userId)
{
var initUserSettingsDTO = new InitUserSettingsDTO();
return initUserSettingsDTO;
}
}
}
As you can see, I am using a complex type as the return type of the only function of the domain service.
What I can not figure out is why on my testing Windows Server 2012 (not a development machine, just a virtual machine used for testing) or on my development machine everything runs without any problem, but on the hosting account it raise the error above.
Does anyone has any idea about this?
Thank you
Try adding the [Invoke] attribute to your InitUserSettings method:
[Invoke]
public InitUserSettingsDTO InitUserSettings(Guid userId)
{
var initUserSettingsDTO = new InitUserSettingsDTO();
return initUserSettingsDTO;
}
Make sure your web.config is set up as described here: http://msdn.microsoft.com/en-us/library/ff426912(v=vs.91).aspx
Being exasperated with this strange situation and the low support I received from the web hosting company, I have tried the same thing with another web provider. As I was thinking, it was working this time with no problems, so my assumption that the original provider had poor support for WCF RIA Services (or maybe other unidentified problem) was correct.
I have a WPF application which calls WCF service methods through a Client which exposes these methods. Is there any way to bind my application to a property of the service, and to get notified when this property changes? I know INotifyPropertyChanged but I have some doubts about its efficiency in this case... Thanks
EDIT : Actually, all I want is my application to be notified of the changes that happen on the server side.
There are a couple of questsions here. You can bind your code to the client end of a WCF service and by using a partial class definition you can add an INotifyPropertyChanged interface to it so that it meets your design. But actually wiring up the mechanism for pushing updates from the server would be much harder.
In fact, Events will work over WCF, and reasonably performant i.e. you won't have the delay associated with polling. However I wouldn't try to squeeze your WCF code into fitting the INotifyPropertyChanged pattern. Instead use a more bespoke interface for the client/server comms and then expose the INotifyPropertyChanged back in the ViewModel.
Just add a delegate to your service, then call the service from your view model or code behind and reflect the changes with your properties that implement the INotifyPropertyChanged interface:
In Service:
public delegate void ServcieUpdate(SomeDataType data);
public ServcieUpdate OnServcieUpdated { get; set; }
When data is updated:
if (OnServcieUpdated != null) OnServcieUpdated(data);
In view model:
private ServiceClient serviceClient = new ServiceClient();
private ObservableCollection<SomeDataType> data = new
ObservableCollection<SomeDataType>();
public YourViewModel()
{
serviceClient.OnServiceUpdated += OnServcieUpdated;
}
public ObservableCollection<SomeDataType> Data
{
get { return data; }
set { data = value; NotifyPropertyChanged("Data");
}
public void OnServcieUpdated(SomeDataType data)
{
Data = data;
}
Please take a look at the Delegates (C# Programming Guide) page on MSDN in you are unfamiliar with using delegate objects.
I tried to solve by myself, but... Looks like I need help from people.
I have Business Silverlight application with WCF RIA and EntityFramework. Access to Database I get via LinqToEntites.
Common loading data from database I making by this:
return DbContext.Customers
This code returns full Customers table from DataBase. But sometimes I do not need to show all data. Easy way is use linq filters in client side by next code:
public LoadInfo()
{
...
var LO1 = PublicDomainContext.Load(PublicDomainContext.GetCustomersQuery());
LO1.Completed += LO1Completed;
...
}
private void LO1Completed(object sender, EventArgs eventArgs)
{
...
DatatViewGrid.ItemsSource = null;
DatatViewGrid.ItemsSource = loadOperation.Entities.Where(c=>c ...filtering...);
//or PublicDomainContext.Customers.Where(c=>c ...filtering...)
...
}
However this way has very and very important flaw: all data passing from server to client side via DomainService may be viewed by applications like Fiddler. So I need to come up with another way.
Task: filter recieving data in server side and return this data.
Way #1: LinqToEntites has a beautiful projection method:
//MSDN Example
var query =
contacts.SelectMany(
contact => orders.Where(order =>
(contact.ContactID == order.Contact.ContactID)
&& order.TotalDue < totalDue)
.Select(order => new
{
ContactID = contact.ContactID,
LastName = contact.LastName,
FirstName = contact.FirstName,
OrderID = order.SalesOrderID,
Total = order.TotalDue
}));
But, unfortunately, DomainServices cannot return undefined types, so this way won't work.
Way #2: I found next solution - make separate DTO classes (DataTransferObject). I just read some samples and made on the server side next class:
[DataContract]
public partial class CustomerDTO
{
[DataMember]
public int ISN { get; set; }
[DataMember]
public string FIO { get; set; }
[DataMember]
public string Listeners { get; set; }
}
And based this class I made a row of methods which return filtered data:
[OperationContract]
public List<CustomerDTO> Customers_Common()
{
return DbContext.Customers....Select(c => new CustomerDTO { ISN = c.ISN, FIO = c.FIO, Listeners = c.Listeners }).ToList();
}
And this works fine, all good...
But, there is strange problem: running application locally does not affect any troubles, but after publishing project on the Web Site, DomainService returns per each method HTTP 500 Error ("Not Found" exception). Of course, I cannot even LogIn into my application. DomainService is dead. If I delete last class and new methods from application and republish - all works fine, but without speacial filtering...
The Question: what I do wrong, why Service is dying with new classes, or tell me another way to solve my trouble. Please.
U P D A T E :
Hey, finally I solved this!
There is an answer: Dynamic query with WCF RIA Services
Your best shot is to find out what is causing the error. For that, override the OnError method on the DomainService like this:
protected override void OnError(DomainServiceErrorInfo errorInfo)
{
/* Log the error info to a file. Don't forget inner exceptions.
*/
base.OnError(errorInfo);
}
This is useful, because only two exceptions will be passed to the client, so if there are a lot of nested inner exceptions, you should still be able to see what actually causes the error.
In addition, you can inspect the error by attaching the debugger to the browser instance you are opening the site with. In VS2010 this is done by doing [Debug] -> [Attach to Process] in the menu-bar.
I working with:
Class Library: Model.dll
using System;
using System.Collections.Generic;
using System.Text;
namespace root
{
public class Customer
{
private int _Id;
public int Id
{
get { return _Id; }
set { _Id = value; }
}
private string _Name;
public string Name
{
get { return _Name; }
set { _Name = value; }
}
}
}
ASP.NET Web Service with reference to Model.dll so i can use in web method:
[WebMethod]
public string HelloWorld(root.Customer customer) {
return "Hello World";
}
Windows Application with reference to both Model.dll and Web Service (1).
root.Customer newCustomer = new Customer();
newCustomer.Id = 1;
newCustomer.Name = "Name";
ws.Service ws = new root.ws.Service();
ws.HelloWorld(newCustomer);
^ problem here
Error: Argument '1': cannot convert from 'root.Customer' to 'root.ws.Customer'
(1) Right click -> And Web Reference -> Web services in this solution -> Click Service.asmx ->
Enter Web reference name: ws -> Click Add reference
Updated: I can change line in generated Reference.cs file from
public string HelloWorld(Customer customer)
to
public string HelloWorld(root.Customer customer)
So function will be looking for real model instead of proxy object, but is not real answer.
I don't event think about editing this file after each web reference update.
How to force this for using real model?
I am afraid that reusing types in automatically generated ASMX proxies is impossible.
There are three options.
1) write your own code generator that will act like the wsdl.exe i.e. build a proxy of your web service but reusing your specified types
(rather difficult)
2) write your own code rewriter that will rewrite proxies generated automatically to use your own types. You'd invoke such rewriter each time after you build up your reference to the web service
(still tedious)
3) switch to WCF web services. a WCF service on a basicHttpBinding is semantically equivalent to a ASMX web service (uses the same communication protocol based on http + soap) but the WCF service metadata contain more information about types so that the proxy generator is able to "reuse types from referenced assemblies".
(suggested approach)
If you switch away from asmx and start using WCF's svc model, you can share a library between the server and client without much fuss at all. If that is an option, there are plenty of resources to help you out with WCF online.
I've been looking for it, for quite and while, and I didn't really find anything that cover how to pull data trough duplex connection for Silverlight (pollingHttpDuplex).
I have setup basic sub/pub application with duplex.
Now I wanted to get list of topics, that are users are connected to. My first thought, was to setup simple DataContract (with only one field TopicName), then get data from Dicionary that I've been using to store current topics.
So I end up with something like this:
[OperationContract]
public List<Topic> GetTopicList()
{
List<Topic> topicList;
topicList = (from p in _sessionIDTopic
select new Topic
{
TopicName = p.Value
}).ToList<Topic>();
return topicList;
}
[DataContract]
public class Topic
{
[DataMember]
public string TopicName { get; set; }
}
I'm doing something wrong here. Because big question is how to send this to the client (Silverlight 4), and bind it to controls ?
Also duplex is essential for application. Changing it for anything else is not an option.
Using a duplex connection here doesn't have any effect on how you get the data to the client. The example you specified looks like simple one way communication. To do that, your client project needs a service reference to the server, and the generated proxy will provide the methods the client needs to access the operations on the server.
I think you should start by looking at a simple WCF example project to see what I mean. If this is not your problem, please rephrase the question.