/// <summary>
/// Instantiates a new SingleInstanceTracker object.
/// When using this constructor overload and enforcerRetriever is null, the SingleInstanceTracker object can only be used to determine whether the application is already running.
/// </summary>
/// <param name="name">The unique name used to identify the application.</param>
/// <param name="enforcerRetriever">The method which would be used to retrieve an ISingleInstanceEnforcer object when instantiating the new object.</param>
/// <exception cref="System.ArgumentNullException">name is null or empty.</exception>
/// <exception cref="SingleInstancing.SingleInstancingException">A general error occured while trying to instantiate the SingleInstanceInteractor. See InnerException for more details.</exception>
public SingleInstanceTracker(string name, SingleInstanceEnforcerRetriever enforcerRetriever)
{
if (string.IsNullOrEmpty(name))
{
throw new ArgumentNullException("name", "name cannot be null or empty.");
}
try
{
singleInstanceMutex = new Mutex(true, name, out isFirstInstance);
// Do not attempt to construct the IPC channel if there is no need for messages
if (enforcerRetriever != null)
{
string proxyObjectName = "SingleInstanceProxy";
string proxyUri = "ipc://" + name + "/" + proxyObjectName;
// If no previous instance was found, create a server channel which will provide the proxy to the first created instance
if (isFirstInstance)
{
// Create an IPC server channel to listen for SingleInstanceProxy object requests
ipcChannel = new IpcServerChannel(name);
// Register the channel and get it ready for use
ChannelServices.RegisterChannel(ipcChannel, false);
// Register the service which gets the SingleInstanceProxy object, so it can be accessible by IPC client channels
RemotingConfiguration.RegisterWellKnownServiceType(typeof(SingleInstanceProxy), proxyObjectName, WellKnownObjectMode.Singleton);
// Attempt to retrieve the enforcer from the delegated method
ISingleInstanceEnforcer enforcer = enforcerRetriever();
// Validate that an enforcer object was returned
if (enforcer == null)
{
throw new InvalidOperationException("The method delegated by the enforcerRetriever argument returned null. The method must return an ISingleInstanceEnforcer object.");
}
// Create the first proxy object
proxy = new SingleInstanceProxy(enforcer);
// Publish the first proxy object so IPC clients requesting a proxy would receive a reference to it
RemotingServices.Marshal(proxy, proxyObjectName);
}
else
{
// Create an IPC client channel to request the existing SingleInstanceProxy object.
ipcChannel = new IpcClientChannel();
// Register the channel and get it ready for use
ChannelServices.RegisterChannel(ipcChannel, false);
// Retreive a reference to the proxy object which will be later used to send messages
proxy = (SingleInstanceProxy)Activator.GetObject(typeof(SingleInstanceProxy), proxyUri);
// Notify the first instance of the application that a new instance was created
// proxy.Enforcer.OnNewInstanceCreated(new EventArgs());
}
}
}
catch (Exception ex)
{
throw new SingleInstancingException("Failed to instantiate a new SingleInstanceTracker object. See InnerException for more details.", ex);
}
}
/// <summary>
/// Instantiates a new SingleInstanceProxy object.
/// </summary>
/// <param name="enforcer">The enforcer (first instance of the application) which will receive messages from the new instances of the application.</param>
/// <exception cref="System.ArgumentNullException">enforcer is null.</exception>
public SingleInstanceProxy(ISingleInstanceEnforcer enforcer)
{
if (enforcer == null)
throw new ArgumentNullException("enforcer", "enforcer cannot be null.");
this.enforcer = enforcer;
}
public static void StartServer(ISingleInstanceEnforcer enforcer)
{
StopServer();
fEnforcer = enforcer;
EnsurePaths();
try {
fFileWatcher = new FileSystemWatcher(GetIpcPath(), fMsgFileName);
fFileWatcher.IncludeSubdirectories = false;
fFileWatcher.NotifyFilter = (NotifyFilters.CreationTime | NotifyFilters.LastWrite);
fFileWatcher.Created += OnFileEvents;
fFileWatcher.Changed += OnFileEvents;
fFileWatcher.EnableRaisingEvents = true;
} catch (Exception ex) {
// Access denied
Logger.LogWrite("IpcFake.StartServer(): " + ex.Message);
}
}