Thursday, 4 October 2012

WP7 game/app talking to WCF Web Services

This post is taken from the discussion we had on the forum here. So, the OP was asking about WCF web services and I replied with my 2 peneth and said I would write a blog post about it, and this is where I will start.
Stuff You Will Need (Other than the dev tools)
  1. A host to serve your service
  2. A registered domain with said host
  3. An FTP client
Get a ASP.NET Host
I use TSOHost for all my web hosting, have my domain registered with them and they also serve my web site there. I chose these guys as at the time they gave all I needed in there basic package for ASP.NET and must say I have not a bad word to say about them. Any tech issues I have had; they have responded and resolved in no time at all. Now if I was you, I wouldn’t just take these guys up, I would have a good look round first, make sure you get a good deal.
Create Database
So once you are registered, have your domain up and running, you will want to set up a DB on the server, now I can only show you how I do it with the host I use, it will differ if you use another company to host your site.
From the dashboard the host provide me with I can get to my MySQL DB stuff and set up a new DB


This then gives me the server side IP address for the database so I can then connect to it from my service, we will need this later, don’t worry about it for now, just know we will need it later.
I now need to set up a user for this DB, again from the control panel the host has provided I can do this.


Now we have a database and a user that can access it, what we now need is a table that can be used to store data. Again from the hosts dashboard I can go and create a table in my new DB


Now with the table created I need to create the columns that will be in it.


So, my two columns are Country and Count. So we now have a table set up which will look something like this


Service Creation
Now we need to create a web service to be hosted from our site and have access to the new DB and it’s table(s). We will also have to get some assemblies so we can connect and use a MySQL database, but lets get the basic service project going for now.
Open up VS2010 and create a new Web Site,


As far as creating a WCF web service, you have just done it; it wont do what you want it to yet, but the default project comes with basic stubs so you could run it as it stands and it would run the service. But we don’t want that…
Creating Web Methods
So, we now want to give the service some methods so we can act on the database. First thing I am going to do is rename the source files to reflect this service better.


I am also going to clear out all the stuff we don’t need from this project, all the template code can go really, so in the IRCTestService.cs (was IService.cs) I am removing everything from line 23 on wards, we wont be needing that data contract, we will create our own ones in a moment. I am also going to remove ALL the operational contracts from the interface in this file too, we now have a pretty naked looking file
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;

// NOTE: You can use the "Rename" command on the "Refactor" menu to change the interface name "IService" in both code and config file together.
[ServiceContract]
public interface IRCTestService
{
  
}
But that’s how we want it, ready for us to put our functionality in it. Just so we have all our ducks in a row, clean out the RCTestService.cs file to so it looks like this
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;

// NOTE: You can use the "Rename" command on the "Refactor" menu to change the class name "Service" in code, svc and config file together.
public class RCTestService : IRCTestService
{
  
}
Now, make sure that the RCTestService.svc (was Service.svc) file is using the right class now we have renamed it, like this
<%@ ServiceHost Language="C#" Debug="true" Service="RCTestService" CodeBehind="~/App_Code/RCTestService.cs" %>
Before we can write our first web method we need to understand how we are going to package the data and send it to and from the client, this is done with data contracts, so the first data contract we want will have information in it that we want to have stored on the server. More importantly for me I like to have a base class for all my requests and responses, so lets first create a BaseRequest data contract. Create a new folder file in the App_Code folder and call it DataContracts (nice to keep tidy), then in there create a new class called RequestBase , make sure you specify that the class is a data contract (you have to type it in above the class definition) like this


In this class I am going to have it store a user name and password, we won’t really be doing much validation as this is a simple project, but just to show you how you might want to set it up. So your RequestBase class should now look like this, note you have to specify that the members are Data Members
[DataContract]
public class RequestBase
{
    [DataMember]
    public string UserName { get; set; }

    [DataMember]
    public string Password { get; set; }

    public RequestBase()
    {
        //
        // TODO: Add constructor logic here
        //
    }
}
We now have a base request object, we are now going to create an UpdateRequest data contract, so we can send the client data to the service and it can be stored in the database. In the same folder as the RequestBase.cs file, create another new class called UpdateRequest.cs, derive from RequestBase and add in the fields we want to store in the DB, it should look something like this when you are done
[DataContract]
public class UpdateRequest : RequestBase
{
    [DataMember]
    public string Country { get; set; }

    public UpdateRequest()
    {
        //
        // TODO: Add constructor logic here
        //
    }
}
Now we need to add our first web method, in the interface (IRCTestService.cs) we are going to create our first method like this
[ServiceContract]
public interface IRCTestService
{
    [OperationContract]
    void UpdateServer(UpdateRequest request);
}
We then need to implement this in the service. I am also going to add in some very simple validation, naturally you would be a lot more exhaustive on a real server. Your RCTestService.cs should now look something like this
public class RCTestService : IRCTestService
{
    public void UpdateServer(UpdateRequest request)
    {
        if (ValidRequest(request))
        {
            // Do what we need to do
        }
    }

    private bool ValidRequest(RequestBase request)
    {
        return true;
    }
}


Hit OK, it’s so we can debug the service, we can remove this later, it just adds a setting to the web.config file. So you should then get a screen a little like this


If you get a screen like this


Click the RDTestService.svc file, this is the actual service we want to make sure runs.
Congratulations you have just written your own WCF service!! Still does not do all we need though, and now we will look at how we will interact with the database :)
MySQL
So, we now need to get the MySQL assemblies so we can connect to the DB, you can find the download you needhere. Download and install the msi, I had to uninstall an older version, you may need to do the same.
Once installed you can then reference the MySQL assemblies in your project, right click on the project and select Add Reference like this


In the Add Reference popup, select the .NET tab, wait about 9 hours (not that long really :P) then go find the MySQL.Data reference and add that to your project like this


Now we have registered the MySQL assemblies we can go on to create a class that will handle all our communications with the database. In the App_Code folder create a Utilities folder, in there create a class called DBUtility and add using statements for System.Data, MySql.Data and MySql.Data.MySqlClient like this
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data;

using MySql.Data;
using MySql.Data.MySqlClient;

/// <summary>
/// Summary description for DBUtility
/// </summary>
public class DBUtility
{
    public DBUtility()
    {
        //
        // TODO: Add constructor logic here
        //
    }
}
Now we are going to add a database connection object, alter the constructor to initialize it and add a method to use it like this
public class DBUtility
{
    public IDbConnection CNN;

    public DBUtility(string server,string port, string database,string userID,string password)
    {
        CNN = new MySqlConnection(string.Format("Data Source={0};Port={1};Database={2};User ID={3};Password={4}", server, port, database, userID, password));      
    }

    public DataSet GetDataSet(string sql)
    {
        DataSet ds = new DataSet();
        IDbDataAdapter da;

        da = new MySqlDataAdapter(sql, (MySqlConnection)CNN);

        da.Fill(ds);

        return ds;
    }
}
As you can see in this sample I am using IDbConnection interface rather than a MySQLConnection, this is so later (if I get around to it) we will expand this class so it can connect to databases of other types like MSSql, Oracle and other OleDB types.
So, now we have all this set up we can code up our web method to update the table for us. To the RCTestService.cs we are going to add an instance of DBUtility, in the service constructor, initiate it and then use it in our web method to update the database. In order to do this we are going to set up some values in the web.config file, we are going to add an appSettings section and give it two keys, Server and Port like this
<?xml version="1.0"?>
<configuration>
  <appSettings>
    <add key="Server" value=""/>
    <add key="Port" value=""/>    
  </appSettings>
  <system.web>
    <compilation debug="true" targetFramework="4.0">
      <assemblies>
        <add assembly="MySql.Data, Version=6.4.4.0, Culture=neutral, PublicKeyToken=C5687FC88969C44D"/>
      </assemblies>
    </compilation>
  </system.web>
  <system.serviceModel>
    <behaviors>
      <serviceBehaviors>
        <behavior>
          <!-- To avoid disclosing metadata information, set the value below to false and remove the metadata endpoint above before deployment -->
          <serviceMetadata httpGetEnabled="true"/>
          <!-- To receive exception details in faults for debugging purposes, set the value below to true.  Set to false before deployment to avoid disclosing exception information -->
          <serviceDebug includeExceptionDetailInFaults="false"/>
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <serviceHostingEnvironment multipleSiteBindingsEnabled="true"/>
  </system.serviceModel>
  <system.webServer>
    <modules runAllManagedModulesForAllRequests="true"/>
  </system.webServer>
</configuration>
These values will be populated with the server and port number your data base is on, you can find this value in the MySQL Databases tab on your hosted control panel. I do this as you can test your service while running from your home machine, but you will need to swap the server and port numbers for those used for remote access, you will also need to set up your IP address so it will be allowed to talk to the server during testing, all this is pretty simple on my hosts control panel, just goto the MySQL Remote Access tab.
So, now we have our server and port configured we can set up the connection object in the service constructr like this
public class RCTestService : IRCTestService
{
    protected DBUtility dbUtil;

    public RCTestService()
    {
        dbUtil = new DBUtility(ConfigurationManager.AppSettings["Server"], ConfigurationManager.AppSettings["Port"], "randomch_testdb", "randomch_test", "test");
    }
And we can then update our UpdateServer web method like this
    public void UpdateServer(UpdateRequest request)
    {
        if (ValidRequest(request))
        {
            // Do we have any of this country?
            string sql = string.Format("SELECT * FROM TestTable WHERE Country = '{0}'", request.Country);
            DataSet ds = dbUtil.GetDataSet(sql);

            // Update DB
            if (ds != null && ds.Tables != null && ds.Tables.Count > 0 && ds.Tables[0].Rows.Count > 0)
                sql = string.Format("UPDATE TestTable SET Count = {1} WHERE Country = '{0}'", request.Country, int.Parse(ds.Tables[0].Rows[0]["Count"].ToString()) + 1);
            else
                sql = string.Format("INSERT INTO TestTable VALUES('{0}',{1})", request.Country, 1);

            dbUtil.GetDataSet(sql);
        }
    }
So, what I am doing here, is first checking if we have any records for this country type, if we have then we update that row with a new count value, if we don’t  then we insert a new row.
We can also add a new web method now to get us all the data in the table so we ca display it on our client. Before we do this we need to create a decent response object so we can bundle all that data up and pass it back to the client in a nice tidy manner. We do this with another data contract, but first we will create a ResponseBase and then derive from that.
As before in the DataContracts folder create a new class, but this time call it ResponseBase like this
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;

/// <summary>
/// Summary description for ResponseBase
/// </summary>
[DataContract]
public class ResponseBase
{
    [DataMember]
    public bool Success { get; set; }

    [DataMember]
    public string Message { get; set; }

    public ResponseBase()
    {
        Success = true;
    }
}
We can use this response object in our existing web method, so we can inform the client if all went well or if there was an issue, first we update the service interface so it looks like this
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;

// NOTE: You can use the "Rename" command on the "Refactor" menu to change the interface name "IService" in both code and config file together.
[ServiceContract]
public interface IRCTestService
{
    [OperationContract]
    ResponseBase UpdateServer(UpdateRequest request);
}
Then alter the web method like this
    public ResponseBase UpdateServer(UpdateRequest request)
    {
        ResponseBase retVal = new ResponseBase();

        try
        {
            throw new Exception("oops");
            if (ValidRequest(request))
            {
                // Do we have any of this country?
                string sql = string.Format("SELECT * FROM TestTable WHERE Country = '{0}'", request.Country);
                DataSet ds = dbUtil.GetDataSet(sql);

                // Update DB
                if (ds != null && ds.Tables != null && ds.Tables.Count > 0 && ds.Tables[0].Rows.Count > 0)
                    sql = string.Format("UPDATE TestTable SET Count = {1} WHERE Country = '{0}'", request.Country, int.Parse(ds.Tables[0].Rows[0]["Count"].ToString()) + 1);
                else
                    sql = string.Format("INSERT INTO TestTable VALUES('{0}',{1})", request.Country, 1);

                dbUtil.GetDataSet(sql);
            }
            else
            {
                retVal.Success = false;
                retVal.Message = "Invalid Request Credentials!";
            }
        }
        catch (Exception e)
        {
            retVal.Success = false;
            retVal.Message = e.Message;
        }

        return retVal;
    }
Now onto our new web method, GetAll, this will need a specific response object, but first we need a class to store our data.
Create a new folder called DataObjects, in there create a class called TableData like this
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data;

/// <summary>
/// Summary description for TableData
/// </summary>
public class TableData
{
    public string Country { get; set; }
    public int Count { get; set; }

    public TableData()
    { }

    public TableData(string country, int count)
    {
        Country = country;
        Count = count;
    }
    public TableData(DataRow row)
    {
        Country = row["Country"].ToString();
      
        int c = 0;
        int.TryParse(row["Count"].ToString(), out c);
      
        Count = c;
    }
}
This class will store the two columns we need for each record, I have given it 3 constructors so I can be lazy when creating the objects, but you can define yours how ever you need to.
Now again, create a new class in the DataContracts folder called GetAllResponse deriving from ResponseBase like this
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;
using System.Data;

/// <summary>
/// Summary description for GetAllResponse
/// </summary>
[DataContract]
public class GetAllResponse : ResponseBase
{
    [DataMember]
    IList<TableData> Data { get; set; }

    public GetAllResponse()
    { }

    public GetAllResponse(DataRowCollection rows)
    {
        Data = new List<TableData>();

        foreach (DataRow row in rows)
            Data.Add(new TableData(row));
    }
}
In here we have a list of TableData and a constructor that will populate the object from a DataRowCollection, again so I can be lazy and just pass in the rows from the dataset :)
Now we can create our new Web method to get it all for us, in the interface, set up the call like this
    [OperationContract]
    GetAllResponse GetAll(RequestBase request);
We can then write the web method in the service located in the RCTestService.cs file like this
    public GetAllResponse GetAll(RequestBase request)
    {
        GetAllResponse retVal = new GetAllResponse();
        try
        {
            if (ValidRequest(request))
            {
                // Do our SQL stuff here
            }
            else
            {
                retVal.Success = false;
                retVal.Message = "Invalid Request Credentials!";
            }
        }
        catch (Exception e)
        {
            retVal.Success = false;
            retVal.Message = e.Message;
        }

        return retVal;
    }
Now we can add the logic like this
    public GetAllResponse GetAll(RequestBase request)
    {
        GetAllResponse retVal = new GetAllResponse();
        try
        {
            if (ValidRequest(request))
            {
                string sql = "SELECT * FROM TestTable";
                DataSet ds = dbUtil.GetDataSet(sql);

                if (ds != null && ds.Tables != null && ds.Tables.Count > 0 && ds.Tables[0].Rows.Count > 0)
                    retVal = new GetAllResponse(ds.Tables[0].Rows);
                else
                {
                    retVal.Message = "There is no data in the table...";
                }
            }
            else
            {
                retVal.Success = false;
                retVal.Message = "Invalid Request Credentials!";
            }
        }
        catch (Exception e)
        {
            retVal.Success = false;
            retVal.Message = e.Message;
        }

        return retVal;
    }
Publish the Web Service
So, now we are going to put the service up on the interwebz so your applications can access it. First of all, if you did use the debug/remote access server address and port in your web.config file, switch it to the live IP and port now, if you forget, most FTP clients will let you edit files on the server, so it’s no big issue, just makes it a bit easier if you do it now.
Once you are all compiled and ready to go, you need to locate the MySql.Data.dll as this wont be present on the server, it will be in the GAC, so I found mine here “C:\Windows\Microsoft.NET\assembly\GAC_MSIL”, once you have located the assembly, create an ASP.NET Bin folder in the project ad copy the assembly across so it’s ready to go on the server, your solution should now look something like this


Now, I had a few issues setting mine up on my server as I had other web applications using an older version of the MySQL.Data.dll, to get round this I altered the reference to the assembly so it looked like this
  <add assembly="MySql.Data, Culture=neutral"/>
This means it won’t look for a specific version of the assembly, I also have a Bin folder at a higher level to this service on my server, so I ended up having to use the older version. Also my host does not have Front Page Publishing enabled (probably because I didn’t ask for it) so I have had to set it all up manually rather than using the Publish Web site option in VS2010.
So, we have the project all lined up and ready to be served on our server, fire up your FTP client and connect to your host, create a folder to hold the service, I just used the folder name my project is in RCTestWCFService, then just copy it all up. We are still not done, we need to now go over to our control panel and set up the folder as a virtual directory. With my host it’s a pretty simple thing to do, go into the Virtual Directories option off the main menu screen, select the Add New Virtual Directory tab and enter the names you want as the alias and the name you just transferred the service to and click Create virtual directory.


One more step and we will have our service up and running and that’s to refresh your application pool, I think that by default on my host your site is in a shared application pool, but from the dashboard you can switch to an isolated one, then simply hit the refresh application pool button.
So, now (if I have not took it down yet) you should be able to go and see my version of this test service running from my site here http://www.randomchaos.co.uk/RCTestWCFService/RCTestService.svc which should look something like this


And if you click the link at the top you will get to see the WSDL for the service, which will look like this


So that’s that, you have created a simple WCF Web service, now to look at setting up a WP7 Client to access this service.
XNA WP7 Client
So as I hope you by know, I am pretty much 100% XNA on this blog, so I am going to create the WP7 client in pure XNA. So, create your XNA WP7 project as you normally would, we then need to add a service reference, right click on the project and click Add Service Reference


In the Address paste the address of your service and hit the Go button, once the service has been discovered you can change the namespace that will be used in your project, I named mine RCTestService, then click OK


And that’s it, it’s now bound to the service and we can now make the web service calls from the client.
In the Game1 class I create a reference to the service just above the constructor like this
namespace RCTestWP7Client
{
    /// <summary>
    /// This is the main type for your game
    /// </summary>
    public class Game1 : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;

        RCTestService.RCTestServiceClient webService;

        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";
Then in the Initialize method I am going to instantiate the service and bind callbacks to the asynchronous web methods we have. The methods appear as asynchronous as the WP7 uses the same Silverlight architecture (I am guessing) which forces the service calls to be asynchronous, if we were writing for a PC XNA game we could make synchronous calls. And if we were on the XBox, we could not bind to the service as the framework does not allow it for security reasons.
So our Initialize method now looks something like this and we have two new methods
        protected override void Initialize()
        {
            // TODO: Add your initialization logic here

            base.Initialize();

            webService = new RCTestService.RCTestServiceClient();
            webService.UpdateServerCompleted += new EventHandler<RCTestService.UpdateServerCompletedEventArgs>(webService_UpdateServerCompleted);
            webService.GetAllCompleted += new EventHandler<RCTestService.GetAllCompletedEventArgs>(webService_GetAllCompleted);
        }

        void webService_GetAllCompleted(object sender, RCTestService.GetAllCompletedEventArgs e)
        {
            throw new NotImplementedException();
        }

        void webService_UpdateServerCompleted(object sender, RCTestService.UpdateServerCompletedEventArgs e)
        {
            throw new NotImplementedException();
        }
I am going to create a bool so I know if I have updated the server and in the Update method if we have not done it, call the UpdateServer web method
        protected override void Update(GameTime gameTime)
        {
            // Allows the game to exit
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
                this.Exit();

            if (!UpdatedServer)
            {
                UpdatedServer = true;
                RCTestService.UpdateRequest req = new RCTestService.UpdateRequest();
                req.UserName = "username";
                req.Password = "password";
                req.Country = System.Globalization.CultureInfo.CurrentCulture.Name;

                webService.UpdateServerAsync(req);
            }

            base.Update(gameTime);
        }
Now, what if something goes wrong, then we sort of need a pop up message box to display any issues, so here is a method we can use to do that
        public void ShowMessageBox(string title, string message)
        {
            Guide.BeginShowMessageBox(title, message, new string[] { "OK" }, 0, MessageBoxIcon.Alert, null, null);
        }
So, with that we can then see how our call went and respond accordingly.
        void webService_UpdateServerCompleted(object sender, RCTestService.UpdateServerCompletedEventArgs e)
        {
            if (e.Result.Success)
                ShowMessageBox("All Good", "Server was updated.");
            else
                ShowMessageBox("Error", e.Result.Message);
        }
Now we have that call all wired up we can then take on the next one, but first we need to add a font to the content folder so we can show the results, we are also going to call the method every minute and display the updated data and we will hold this data in a list of TableData.
The variables we now have at the top of Game1 look like this
        RCTestService.RCTestServiceClient webService;
        List<RCTestService.TableData> getAllResponse = new List<RCTestService.TableData>();
        TimeSpan checkTimeSpan = new TimeSpan(0, 1, 0);
        TimeSpan lastCheck = DateTime.Now.TimeOfDay;
        bool UpdatedServer = false;
and our list of data is populated when the service returns like this
        void webService_GetAllCompleted(object sender, RCTestService.GetAllCompletedEventArgs e)
        {
            if (e.Result.Success)
            {
                getAllResponse = new List<RCTestService.TableData>(e.Result.Data);
            }
            else
                ShowMessageBox("Error", e.Result.Message);
        }
Now in the Update method we are going to set up the call to the service like this
        protected override void Update(GameTime gameTime)
        {
            // Allows the game to exit
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
                this.Exit();

            if (!UpdatedServer)
            {
                UpdatedServer = true;
                RCTestService.UpdateRequest req = new RCTestService.UpdateRequest();
                req.UserName = "username";
                req.Password = "password";
                req.Country = System.Globalization.CultureInfo.CurrentCulture.Name;

                webService.UpdateServerAsync(req);
            }
            else
            {
                if (DateTime.Now.TimeOfDay - lastCheck > checkTimeSpan)
                {
                    lastCheck = DateTime.Now.TimeOfDay;

                    RCTestService.RequestBase req = new RCTestService.RequestBase();
                    req.UserName = "username";
                    req.Password = "password";

                    webService.GetAllAsync(req);
                }
            }

            base.Update(gameTime);
        }
So, now we are going to display on the screen the time till next check and the current data we have, so our draw call will now look like this
        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.Black);

            spriteBatch.Begin();

            spriteBatch.DrawString(Content.Load<SpriteFont>("Fonts/font"), string.Format("Next Check in {0} seconds", (checkTimeSpan - (DateTime.Now.TimeOfDay - lastCheck)).Seconds), Vector2.Zero, Color.Gold);

            int cnt = getAllResponse.Count;
            for (int l = 0; l < cnt; l++)
                spriteBatch.DrawString(Content.Load<SpriteFont>("Fonts/font"), string.Format("{0}        {1}", getAllResponse[l].Country, getAllResponse[l].Count), new Vector2(0, Content.Load<SpriteFont>("Fonts/font").LineSpacing * (l + 1)), Color.White);

            spriteBatch.End();

            base.Draw(gameTime);
        }
So, when our WP7 app connects to the service we get this


And once it has gone and got all, looks something like this


Silverlight WP7 Client
So, I am updating this post to include the silver light client code, I am new to Silverlight on the WP7, so please forgive how crude I have been writing this client. It’s pretty much the same steps as the XNA client, we add a reference to the service, just as before, but we set the service up in code in the MainPage constructor like this
        public MainPage()
        {
            InitializeComponent();

            webService = new RCTestService.RCTestServiceClient();
            webService.UpdateServerCompleted += new EventHandler<RCTestService.UpdateServerCompletedEventArgs>(webService_UpdateServerCompleted);
            webService.GetAllCompleted += new EventHandler<RCTestService.GetAllCompletedEventArgs>(webService_GetAllCompleted);

            RCTestService.UpdateRequest request = new RCTestService.UpdateRequest();
            request.UserName = "username";
            request.Password = "password";
            request.Country = System.Globalization.CultureInfo.CurrentCulture.Name;

            webService.UpdateServerAsync(request);

            runThread = true;
            timer.Start();

            txtCounter.Text = string.Format("Data will be updated every {0} seconds.", checkTimeSpan.Seconds);
        }
And the callback methods are also pretty much the same
        void webService_GetAllCompleted(object sender, RCTestService.GetAllCompletedEventArgs e)
        {
            if (e.Result.Success)
            {
                getAllResponse = new List<RCTestService.TableData>(e.Result.Data);

                RunAsCrossThreadSafeCode(
                                delegate
                                {
                                    txtData.Text = string.Empty;
                                    foreach (RCTestService.TableData data in getAllResponse)
                                    {
                                        txtData.Text += string.Format("{0}        {1}\n", data.Country, data.Count);
                                    }
                                });


            }
            else
                MessageBox.Show("Error", e.Result.Message, MessageBoxButton.OK);
        }

        void webService_UpdateServerCompleted(object sender, RCTestService.UpdateServerCompletedEventArgs e)
        {
            if (e.Result.Success)
            {
                MessageBox.Show("All Good", "Server was updated.", MessageBoxButton.OK);
            }
            else
                MessageBox.Show("Error", e.Result.Message, MessageBoxButton.OK);
        }
But as you can see I have had to do some extra work to be able to populate the TextBlock control from the callback. This is because the code calling the service method is being called from another thread. I am doing this as in Silverlight I don’t have a game loop, so as in XNA we can just up a check in the Update method, here I have fired off a new thread and do they check in there, the tread looks like this
        static void callTimer()
        {
            while (runThread)
            {
                if (DateTime.Now.TimeOfDay - lastCheck > checkTimeSpan)
                {
                    lastCheck = DateTime.Now.TimeOfDay;

                    RCTestService.RequestBase req = new RCTestService.RequestBase();
                    req.UserName = "username";
                    req.Password = "password";

                    webService.GetAllAsync(req);
                }
                Thread.Sleep(1);
            }
        }
Also the RunAsCrossThreadSafeCode is mine (well after I used Google to find out how to do it) and that method looks like this
        /// <summary>
        /// Method to run a delegate as cross thread safe code
        /// </summary>
        /// <param name="code">Code to be ran</param>
        protected static void RunAsCrossThreadSafeCode(CrossThreadCode code)
        {
            using (AutoResetEvent are = new AutoResetEvent(false))
            {
                System.Windows.Deployment.Current.Dispatcher.BeginInvoke(() =>
                {
                    // Code here
                    code();

                    are.Set();
                });
                are.WaitOne();
            }
        }
As you can see it takes a CrossThreadCode delegate, again created at the top of the class like this
        /// <summary>
        /// Delegate used to run none cross thread safe code in a cross thread safe manor.
        /// </summary>
        protected delegate void CrossThreadCode();



And that’s pretty much it really. I know it seems like a lot to sort out and to take in at first, but once you have written a few services you will love it, I do :) I know I may go around the houses and do stuff the long winded way, so if you read this and have any advice or tips to add then please feel free to comment and let us all know how you stream line the process. Or you know of a great host for ASP.NET, share that too. If you have any issues creating your WCF service then let us know, you never know we might be able to help :P
Hope I have not scared you off of confused you when it comes to creating services for your game, and I hope this post helps you realize the potential you have in your game with web services.
ALL the source is available here [Not yet uploaded]

2 comments:

  1. Thank you SO much for this tutorial.
    Finally I got a decent metrics collecting service up on my hobby video game! This is worth so much to me.
    Thank you so much!!!

    ReplyDelete
    Replies
    1. Cool, glad you found the post useful :)

      Delete