What is the correct way to create a single-instance WPF application?

Question

Using C# and WPF under .NET (rather than Windows Forms or console), what is the correct way to create an application that can only be run as a single instance?

I kno

Answer 1

Well, I have a disposable Class for this that works easily for most use cases:

Use it like this:

static void Main()
{
    using (SingleInstanceMutex sim = new SingleInstanceMutex())
    {
        if (sim.IsOtherInstanceRunning)
        {
            Application.Exit();
        }

        // Initialize program here.
    }
}

Here it is:

/// 

/// Represents a  class.
/// 
public partial class SingleInstanceMutex : IDisposable
{
    #region Fields

    /// 

    /// Indicator whether another instance of this application is running or not.
    /// 
    private bool isNoOtherInstanceRunning;

    /// 

    /// The  used to ask for other instances of this application.
    /// 
    private Mutex singleInstanceMutex = null;

    /// 

    /// An indicator whether this object is beeing actively disposed or not.
    /// 
    private bool disposed;

    #endregion

    #region Constructor

    /// 

    /// Initializes a new instance of the  class.
    /// 
    public SingleInstanceMutex()
    {
        this.singleInstanceMutex = new Mutex(true, Assembly.GetCallingAssembly().FullName, out this.isNoOtherInstanceRunning);
    }

    #endregion

    #region Properties

    /// 

    /// Gets an indicator whether another instance of the application is running or not.
    /// 
    public bool IsOtherInstanceRunning
    {
        get
        {
            return !this.isNoOtherInstanceRunning;
        }
    }

    #endregion

    #region Methods

    /// 

    /// Closes the .
    /// 
    public void Close()
    {
        this.ThrowIfDisposed();
        this.singleInstanceMutex.Close();
    }

    public void Dispose()
    {
        this.Dispose(true);
        GC.SuppressFinalize(this);
    }

    private void Dispose(bool disposing)
    {
        if (!this.disposed)
        {
            /* Release unmanaged ressources */

            if (disposing)
            {
                /* Release managed ressources */
                this.Close();
            }

            this.disposed = true;
        }
    }

    /// 

    /// Throws an exception if something is tried to be done with an already disposed object.
    /// 
    /// 
    /// All public methods of the class must first call this.
    /// 
    public void ThrowIfDisposed()
    {
        if (this.disposed)
        {
            throw new ObjectDisposedException(this.GetType().Name);
        }
    }

    #endregion
}