How can I connect my silverlight application with SQL server 2005 - asp.net

I am trying to connect my silverlight application with Sql server 2005 for login purpose. I am totally new to silverlight and want to build my own website in Silverlight. Please suggest useful sites for referance. Thanx in advance.

This may help you
http://www.codeproject.com/Articles/37522/7-Simple-Steps-to-Connect-SQL-Server-using-WCF-fro

You have to use a Web Service example WCF.
1)Add a WCF to your project.
//This is your interface Class.
namespace SilverlightApplication1.Web
{
[ServiceContract]
public interface IService1
{
[OperationContract]
bool UserLogin(string email, string password);
}
}
//This is your service code behind class
namespace SilverlightApplication1.Web
{
public class Service1 : IService1
{
public bool UserLogin(string email,string password)
{
// Your logic here to verify user name and password
}
}
}
//After creating the service. Add a reference to your application.**
2) Add the Service Reference to your Silverlight application.
Right click on your project, Select the web references option and add the service to your project. Now if you have a button control on your form which will submit the data to your wcf service. Add the following code in its click event.
Service1Client proxy ;
private void button1_Click(object sender, RoutedEventArgs e)
{
proxy.UserLogin += new EventHandler<InsertDataCompletedEventArgs>(proxy_UserLogin);
proxy.UserLogin(txtEmail.Text, "Password");
}
void proxy_UserLogin(object sender, InsertDataCompletedEventArgs e)
{
if (e.Result == true)
{
lblMesg.Content = "User Login successfully";
}
else
{
lblMesg.Content = "User record not found";
}
}
In the button Click event call that service.

If you want a SQL Server connection for logging on, you can create a Silverlight Business Application project. It has user logon built in. This way, you can concentrate on the rest of your Silverlight application's features.

Related

Pass User info to WCF Web service with WCF method vs with Soap header

My WCF Webservice provide all data manipulation operations and my ASP .Net Web application present the user interface.
I need to pass user information with many wcf methods from ASP .Net app to WCF app.
Which one in is better approach regarding passing user info from web app to web service?
1) Pass user information with SOAP header?
ASP .Net Application has to maintain the number of instances of WCF Webservice client as the number of user logged in with the web application. Suppose 4000 user are concurrently active, Web app has to maintain the 4000 instances of WCF webserice client.
Is it has any performance issue?
2) Pass user information with each method call as an additional parameter?
Every method has to add this addtional paramter to pas the user info which does not seems a elegant solution.
Please suggest.
regards,
Dharmendra
I believe it's better to pass some kind of user ID in a header of every message you send to your WCF service. It's pretty easy to do, and it's a good way to get info about user + authorize users on service-side if needed. And you don't need 4000 instances of webservice client for this.
You just need to create Behavior with Client Message Inspector on client side(and register it in your config). For example:
public class AuthClientMessageInspector: IClientMessageInspector
{
public void AfterReceiveReply(ref Message reply, object correlationState)
{
}
public object BeforeSendRequest(ref Message request, IClientChannel channel)
{
request.Headers.Add(MessageHeader.CreateHeader("User", "app", "John"));
return null;
}
}
public class ClientBehavior : IEndpointBehavior
{
public void AddBindingParameters(ServiceEndpoint endpoint, BindingParameterCollection bindingParameters)
{
}
public void ApplyClientBehavior(ServiceEndpoint endpoint, ClientRuntime clientRuntime)
{
foreach (var operation in endpoint.Contract.Operations)
{
operation.Behaviors.Find<DataContractSerializerOperationBehavior>().MaxItemsInObjectGraph = Int32.MaxValue;
}
var inspector = new AuthClientMessageInspector();
clientRuntime.MessageInspectors.Add(inspector);
}
public void ApplyDispatchBehavior(ServiceEndpoint endpoint, EndpointDispatcher endpointDispatcher)
{
}
public void Validate(ServiceEndpoint endpoint)
{
}
}
And extract it from your service-side:
var headers = OperationContext.Current.IncomingMessageHeaders;
var identity = headers.GetHeader<string>("User", "app");

Get names of Online users connected to a Server

I am new to asp.net. I have gone through this link which has shown how to count the online users connected to a server using asp.net. (which is working when I tried)
My question is: What should I change in that code (Global.asax) so that It shows all the names of the connected users instead of counting them.
I created a chat application which stores the name of the connected user in a variable chatUsername in js file as shown below:
js file
var chatUsername = window.prompt("Enter Username:", "");
//
chat.client.addMessage = //Function
//
chat.server.send(chatUsername);
.aspx.cs file
//Using SignalR (I think this doesnt matter)
public class Chat : Hub
{
public void Send(string from)
{
// Call the addMessage method on all clients
Clients.All.addMessage(from);
}
}
You can find my complete code here
EDIT: Please provide a simple example related only to asp.net or signalr (no other technologies like MVC)
Please help.
Edit: following code refers to SignalR v0.5, not the latest 1.0Alpha2, but I believe the reasoning is the same
To do this you need to add several steps to your SignalR connection process, both in the server and in the client:
on the server side:
on application start-up, for example, you can instantiate a static in-memory repository (can be a dictionary of ) that will serve as the user repository to store all currently connected users.
In the hub you need to handle the Disconnect event (when a user disconnects, needs to be removed from the user repository as well) and notify all other clients that this user disconnected
In the hub you need to add two new methods (the names can be whatever you want) that will help client connect to the system and get the list of currently connected users:
GetConnectedUsers() that just returns a collection of connected users
Joined() where the Hub will create a new User, using the info stored in the round-trip state (the username selected by the client) and the SignalR connection ID, and add the newly created user to the in-memory repository.
on the client side:
First you need to instantiate the javascript object that relates to your server-side hub
var chat = $.connection.chat;
chat.username = chatUsername;
Then implements all the functions that will be called by the hub and finally connect to the hub:
// Step 1: Start the connection
// Step 2: Get all currenlty connected users
// Step 3: Join to the chat and notify all the clients (me included) that there is a new user connected
$.connection.hub.start()
.done(function () {
chat.getConnectedUsers()
.done(/*display your contacts*/);
});
}).done(function () {
chat.joined();
});
});
});
If you are asking why we need to add a stage like "chat.joined()" is because in the method on the Hub that is handling the connection event, the round-trip state is not yet available, so the hub cannot retrieve the username chosen by the user.
Anyway I made a blog post to show more in detail how to create a basic SignalR chat web application using Asp.Net MVC, and it is available at:
http://thewayofcode.wordpress.com/2012/07/24/chatr-just-another-chat-application-using-signalr/
In the post you will also find a link to the github repository where the source is published.
I hope this helps.
Valerio
Apparently, you are using Signal-R - so try tracking state of online users (i.e. connected clients) in java-script itself. Use Connected/Disconnected/Reconnected server side events to broadcast to all clients - from documentation:
public class Chat : Hub
{
public override Task OnConnected()
{
return Clients.All.joined(Context.ConnectionId, DateTime.Now.ToString());
}
public override Task OnDisconnected()
{
return Clients.All.leave(Context.ConnectionId, DateTime.Now.ToString());
}
public override Task OnReconnected()
{
return Clients.All.rejoined(Context.ConnectionId, DateTime.Now.ToString());
}
}
A global server side store (for example - a static dictionary) can be used to store state against the connection id - that way, this dictionary can give you users for needed connection ids. For example,
// dis-claimer: untested code - just to give the idea/hint/outline
public class Chat : Hub
{
// change to use Concurrent Dictionary (or do thread-safe access)
static Dictionary<string, User> _users = new Dictionary<string, User>()
// call from client when it goes online
public void Join(string name)
{
var connId = this.Context.ConnectionId;
__users.Add(connId, new User(connId, name));
}
public override Task OnConnected()
{
return Clients.All.joined(_users[Context.ConnectionId], DateTime.Now.ToString());
}
public override Task OnDisconnected()
{
var user = _users[Context.ConnectionId];
_users.Remove(Context.ConnectionId);
return Clients.All.leave(user, DateTime.Now.ToString());
}
public List<User> GetUsers()
{
return _users.Values.ToList()
}
}
I think this should work for you :-
void Application_Start(object sender, EventArgs e)
{
// Code that runs on application startup
Application["OnlineUsers"] = 0;
List<string> list = new List<string>();
}
//First check if it is Authenticated request:-
void Session_Start(object sender, EventArgs e)
{
if(Request.IsAuthenticated)
list.Add(User.Identity.Name);
//your rest of code .......
}
list will return you all the username who are online :-

Building ASP.Net custom authorization against database without MVC

this is my first request, so don´t be too hard. :)
We are building an Sharepoint 2010 - Application, which consists of some Sharepoint Web Parts and many ASP.Net-Sites. Therefore we are limited to use ASP.Net without MVC. This decision is made and can´t be refused.
We are using Windows Authentification with Impersonation. The Users are stored in an application database. Along with the users there are roles which have rights to specific objects and specific actions. all these informations are stored in the custom database.
The database has a data access layer (EF 4.0). Because Sharepoint is limited to .NET Framework 3.5, the business logic consists of a WCF Data Service which is using the DAL and business logic libary which accessing the WCF Data Service to grab the required information.
The ASP.Net-Pages and Sharepoint Web Parts are directly accessing the business logic.
What i now need is some kind of a Manager-Class which is checking the user against the database to authorize him to access the specific objects. I dont want to do it programmaticly. I want to use annotations to specify if a method from the business layer can be called or not. Furthermore i want to hide some things in the ASP.Net Sites without an programmaticly if-clause.
Can someone give me a hint to achieve this? Is there a way do customize some part of the standard framework to realize it?
The user and his roles and rights i want to store in a session. Is this a good way? the application is accessible only in local network.
Welcome to stackoverflow! A few thoughts on this -
You may be better suited to ask these questions at the cousin site http://sharepoint.stackexchange.com.
This depends on your web farm architecture. If your web front end and data sources are on the same server, then it should be simple to use windows authentication to determine the current user. However, if your web front ends and data sources are on separate servers, then you've reached a limitation due to the "double hop" scenario, where the user's credentials cannot be shared to the server behind the sharepoint server - so to speak.
To work around, investigate using Kerberos authentication in your SharePoint environment, which allows SharePoint to track user credentials throughout the farm - http://blogs.technet.com/b/tothesharepoint/archive/2010/07/22/whitepaper-configuring-kerberos-authentication-for-sharepoint-2010-and-sql-server-2008-r2-products.aspx
Yet another alternative, don't use SharePoint as your application host. Create your web application and deploy it as its own website (http://mysupercoolsite.organization.com), and in SharePoint create a new "web part page", with a "full page vertical" layout. Then, add a "Page Viewer" web part to the page, supplying the url to mysupercoolsite.organization.com. This way, SharePoint is a "portal" to this application for your users, but all authentication, authorization, and structure are based on the application itself, and not at all in SharePoint.
We have stayed at sharepoint as application host.
I´ve implemented a Custom UserControl which implements all the security questions.
public partial class FMD_RoleEnabledControl : System.Web.UI.UserControl
{
public string EnabledRoles { get; set; }
public bool HasDataBinding { get; set; }
public string CurrentUserName
{
get { return Page.User.Identity.Name; }
}
protected override void OnPreRender(EventArgs e)
{
if (!HasDataBinding)
Visible = EnabledRoles.Split(',').Any(rolle => new FMDRoleProvider().IsUserInRole(CurrentUserName, rolle));
base.OnPreRender(e);
}
protected override void OnLoad(EventArgs e)
{
if(HasDataBinding)
Visible = EnabledRoles.Split(',').Any(rolle => new FMDRoleProvider().IsUserInRole(CurrentUserName, rolle));
base.OnLoad(e);
}
}
Custom-RoleProvider
public class FMDRoleProvider : RoleProvider
{
public const string SEPERATOR = ",";
...
public override string[] GetRolesForUser(string username)
{
if (username == null || username == "")
throw new ProviderException("Kein User-Name übergeben"); //TODO
string tmpRollen = "";
RechteManager rm = new RechteManager();
var rollen = rm.GetUserRollen(username);
foreach (var rolle in rollen)
{
tmpRollen += rolle.ROL_Name + SEPERATOR;
}
if (tmpRollen.Length > 0)
{
//Letzten seperator entfernen
tmpRollen = tmpRollen.Substring(0, tmpRollen.Length - 1);
return tmpRollen.Split(',');
}
return new string[0];
}
...
public override bool IsUserInRole(string userName, string roleName)
{
if (userName == null || userName == "")
throw new ProviderException("User name cannot be empty or null."); //TODO
if (roleName == null || roleName == "")
throw new ProviderException("Role name cannot be empty or null."); //TODO
RechteManager rm = new RechteManager();
return rm.IsUserInRolle(userName, roleName);
}
}
Usage
public partial class CustomControl: FMD_RoleEnabledControl
<custom:CustomControl ID="custom" runat="server" EnabledRoles="Admin" HasDataBinding="True" />
Its only the first approach to check against roles, but it works very well. As a second target i am going to implement extra security stuff like checking against speficic actions. Also the RoleProvider has to be registered in web.config. But time is short ;)

using WCF Callback and asp.net to implement publish/subscribe pattern

This is my first web application with WCF. So please guide me as a new guy.
I'm trying to use WCF Callback to implement publish/subscribe pattern. I would like to send the message from UserA to UserB or UserA to every client at the moment. I got an example from here .
In my app, I use ASP.NET as a client to connect WCF service instead and I found a problem when I subscribe to WCF service.
The WCF service does not hold any other clients object. So when I call GetAllClients(_guid), it will return only 1 client which is itself.
Here is the code in ASP.NET page (I put every control inside updatePanel)
public partial class _Default : System.Web.UI.Page, AlertServiceCallback
{
private AlertServiceClient _client;
private Guid _guid = Guid.NewGuid();
protected void Page_Load(object sender, EventArgs e)
{
InstanceContext context = new InstanceContext(this);
_client = new AlertServiceClient(context);
_client.RegisterClient(_guid);
}
protected void btnGetClients_Click(object sender, EventArgs e)
{
//Try to retrive all active clients
Client[] cs = _client.GetAllClients(_guid);
List<Client> list = new List<Client>(cs);
//Bind to dropDownList to display all active clients
ddlClients.DataSource = list;
ddlClients.DataBind();
}
#region "CallBack"
public void OnRegister(string message)
{
throw new NotImplementedException();
}
public void OnMessageSending(string message)
{
throw new NotImplementedException();
}
#endregion
}
Here is the IService and Service on WCF respectively.
[ServiceContract(Name = "AlertService",Namespace = "http://www.testWcf.com/",
CallbackContract = typeof(IAlertCallBack),SessionMode = SessionMode.Required)]
public interface IAlertService
{
[OperationContract(IsOneWay = true)]
void RegisterClient(Guid id, string name);
[OperationContract(IsOneWay = false)]
List<Client> GetAllClients(Guid id);
[OperationContract(IsOneWay = true)]
void SendMessage(Guid fromId, Guid toId, string message);
}
public interface IAlertCallBack
{
[OperationContract(IsOneWay = true)]
void OnRegister(string message);
[OperationContract(IsOneWay = true)]
void OnMessageSending(string message);
}
public class AlertService : IAlertService
{
private object locker = new object();
private Dictionary<Client, IAlertCallBack> clients = new Dictionary<Client, IAlertCallBack>();
public AlertService() { }
public void RegisterClient(Guid guid)
{
IAlertCallBack callback = OperationContext.Current.GetCallbackChannel<IAlertCallBack>();
//---prevent multiple clients adding at the same time---
lock (locker)
{
clients.Add(new Client { Id = guid, Name = name }, callback);
}
}
public List<Client> GetAllClients(Guid guid)
{
//---get all the clients in dictionary---
return (from c in clients
where c.Key.Id != guid
select c.Key).ToList();
}
...
}
Questions are:
Is it possible to implement this publish/subscribe with ASP.NET and WCF callback? (I already tried on window app and it worked fine)
If it is possible, how can I keep all clients that is connecting to WCF Service so I can use those GuId to call callback method.
Thank you.
I don't know why you don't get list of clients - you should but there are much worse problems with your code.
You can't use WCF callback in ASP.NET application. It cannot work because page lives only to serve single HTTP request - it means it most probably lives only for fraction of second and so also your registration. Even If you will be able to get list of clients you will not be able to call OnRegister or OnMessageSending because there will be no proxy listening for these calls.
Even if you force proxy to live after request processing it will still notify only code behind, not your pages rendered in client browser.
Another problem is that it can work only with net.pipe or net.tcp binding. It will not work with wsDualHttp. It is very problematic to open multiple duplex clients from the same machine when using wsDualHttp.
You are doing it completely wrong. What you need is AJAX polling from client browser to asp.net which will call simple service in your chat system.

How to "un-impersonate" (un-delegate?) in Kerberos

I have a web application using Kerberos to access an external resource useing ASP.NET 3.5 and IIS.
When a user connects with the application, Kerberos authentication auto-magically allows me to connect to external resources acting as the user using delegation. This was not easy to do. It is nice, but I've a problem. Sometimes I need to connect to an external resource using an account with more rights than the user. The service account which the app-pool is running under has the addition rights I need. How can I remove the user's Kerberos identification and connect with Kerberos using the service account running the application pool?
UPDATE
I'm not sure why I am getting no responses at all. I've never seen that before. Please post questions, they may clarify the problem (to me too).
Woring in Kerberos and need an overview of delegation? Read the first part of this answer: https://stackoverflow.com/a/19103747/215752.
I have a class:
public class ProcessIdentityScope : IDisposable
{
private System.Security.Principal.WindowsImpersonationContext _impersonationContext;
private bool _disposed;
public ProcessIdentityScope()
{
_impersonationContext = System.Security.Principal.WindowsIdentity.Impersonate(IntPtr.Zero);
}
#region IDisposable Members
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
protected virtual void Dispose(bool disposing)
{
if (!_disposed)
{
_impersonationContext.Undo();
_impersonationContext.Dispose();
_disposed = true;
}
else
throw new ObjectDisposedException("ProcessIdentityScope");
}
#endregion
}
And I use it like so:
using(ProcessIdentityScope identityScope = new ProcessIdentityScope())
{
// Any code in here runs under the Process Identity.
}
This code is based on this MSDN article: http://msdn.microsoft.com/en-us/library/ms998351.aspx

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