Multiple Sounds in WPF Application

So I’m making a small WPF game, which you can find here by the way 😛, and I come across a confusing and infuriating issue. WPF has two built-in audio players: SoundPlayer and MediaPlayer.

SoundPlayer: Can play audio files that are embedded resources in the application, however, this can only play one sound at once.

MediaPlayer: Cannot play audio files that are embedded resources in the application, however, this can play multiple sounds at once.

I think you can see the issue I was having. I wanted to play some background music in my game as well as some sound effects for certain actions in the game. This meant the easiest way to get this functionality was to use both of these options and save the background music to the local disk as a temporary file. Not as clean as I wanted, but it will do I guess 🤷‍♂️

First, I set up my SoundPlayer as this was the simplest one of the two. I created a new SoundPlayer object using the embedded resource:

private static readonly SoundPlayer _soundOne = new SoundPlayer(WPF.Properties.Resources.soundOne);

Then when I wanted this sound to play, I would simply use:

_soundOne.Play();

Simple enough for the SoundPlayer… Now we move onto the MediaPlayer.

First, I make sure that my audio file is set as an Embedded Resource under the Build Actions in the file’s properties in Visual Studio:

You can see from this, that I have a WAV file called “backgroundmusic.wav” which I need to save to disk, play continuously and then delete once the form is closed.

Now that we have done this, we can create the method for saving the embedded WAV file to the %temp% location on disk. This is how I did that:

public static void SaveMusicToDisk(){
    //This sets up a new temporary file in the %temp% location called "backgroundmusic.wav"
    using (FileStream fileStream = File.Create(Path.GetTempPath() + "backgroundmusic.wav")){
        
        //This them looks into the assembly and finds the embedded resource
        //inside the WPF project, under the assets folder
        //under the sounds folder called backgroundmusic.wav
        //PLEASE NOTE: this will be different to you
        Assembly.GetExecutingAssembly().GetManifestResourceStream("WPF.Assets.Sounds.backgroundmusic.wav").CopyTo(fileStream);
    }
}

Great we have now saved the embedded resource to disk, how can we play this now? 🤷‍♂️

We play this by creating a new MediaPlayer object and using the temp file location to play the audio:

//Create a new MediaPlayer object
private static readonly MediaPlayer _backgroundMusic = new MediaPlayer();

public static void StartBackgroundMusic(){
    //Open the temp WAV file saved in the temp location and called "backgroundmusic.wav"
    _backgroundMusic.Open(new Uri(Path.Combine(Path.GetTempPath(), "backgroundmusic.wav")));
    //Add an event handler for when the media has ended, this way
    //the music can be played on a loop
    _backgroundMusic.MediaEnded += new EventHandler(BackgroundMusic_Ended);
    //Start the music playing
    _backgroundMusic.Play();
}

My BackgroundMusic_Ended method looks like this and just makes sure that the music is always restarted once it has finished:

private static void BackgroundMusic_Ended(object sender, EventArgs e){
    //Set the music back to the beginning
    _backgroundMusic.Position = TimeSpan.Zro;
    //Play the music
    _backgroundMusic.Play();
}

Now that the music is playing continuously on a loop, how do we stop the music, dispose of the object and delete the temp WAV file from disk?

To stop and dispose of the MediaPlayer object is pretty easy, you can use:

public static void StopBackgroundMusic(){
    //Stops the music 
    _backgroundMusic.Stop();
    //Disposes of the MediaPlayer object
    _backgroundMusic.Close();
}

Now we go about removing the WAV file from the disk as we don’t want this to remain on the user’s computer once they have exited the application:

public static void DeleteMusicFromDisk(){
    File.Delete(Path.Combine(Path.GetTempPath(), "backgroundmusic.wav"));
}

DONE! ✔️

With all the above code and a little tinkering to fit your specific setup, you should be able to use multiple sounds at once without an issue. Enjoy!

PowerShell Classes and Class Lists

I found that I could use classes in PowerShell similar to how I use them in C#. I instantly wanted to play with this and I thought I would share this as well.

To create a class in PowerShell, it’s as simple as:

#Person class
class PersonClass{
	[String]$Name
	[Int]$Age
}

This allows a “Person” to be created that has the attributed of a name and an age. Simple stuff.

Say I wanted to have a bunch of these “Person”s in a list, a “People” list if you will. Then I could do something like this:

#Creating a list to hold the people using the PersonClass
$People = New-Object 'System.Collections.Generic.List[PSObject]'

#Creating a new person
$newPerson = [PersonClass]::new()
$newPerson.Name = "Roy Orbison"
$newPerson.Age = "24"

#Adding the new person to the people list
$People.Add($newPerson)

What if I wanted to add something like a “Pets” attribute onto the person? Well, I could create a new class to hold a framework for each pet and create a new list attribute in the PersonClass. Here is my PetClass:

#Pet class
class PetClass{
    [String]$Name
    [Int]$Age
    [String]$Color
}

And here is how I add it to my PersonClass so that I can have a list of pets for each user:

#Person class
class PersonClass{<br>    [String]$Name
    [Int]$Age
    [PetClass[]]$Pets
}

Now its really simple to create a list of people with a list of any pets that they might have. Stitching this all together, it looks like this:

#Person class
class PersonClass{
	[String]$Name
	[Int]$Age
    [PetClass[]]$Pets
}

#Pet class
class PetClass{
    [String]$Name
    [Int]$Age
    [String]$Color
}

#Creating a list to hold the people using the PersonClass
$People = New-Object 'System.Collections.Generic.List[PSObject]'

#Creating a new person
$newPerson = [PersonClass]::new()
$newPerson.Name = "Roy Orbison"
$newPerson.Age = "24"

#Adding pets to the new person
for ($i = 0; $i -le 5; $i++){
    $newPet = [PetClass]::new()
    $newPet.Name = $i
    $newPet.Age = $i + 2
    $newPet.Color = "Brown"

    #Adding the pet to the new person
    $newPerson.Pets += $newPet
}

#Adding the new person to the people list
$People.Add($newPerson)

Above you can see that I have created a new person called “Roy Orbison” with an age of “24” and I have added five pets. The pet names and age aren’t really accurate but it’s good enough for this demonstration.

Continuing from this, I could add as many users as I want or even create new classes to add extra framework information for existing classes.

Searching this information isn’t as straight forward in PowerShell as it is in C# but it’s still quite easy. You can see how I get a list of all the pets that Roy Orbison has below:

$People | Where-Object {$_.Name -eq "Roy Orbison"} | Select-Object -ExpandProperty Pets

Upon finishing this, I realised that it would have been much more appropriate to do the users and albums, instead of pets. But I’m far too lazy to change what I already have…

Enjoy!

Caliburn.Micro MVVM Boolean To Visibility Converter

Say I wanted to toggle the visibility of a WPF object in an MVVM way, what would I need to do?

Here is what I currently have:

  • ViewModels
    • ShellViewModel
    • LoadingViewModel
  • Views
    • ShellView
    • LoadingView

When the application is loaded, the ShellViewModel is used to display the LoadingView in a ContentControl object. I have a button on there that I want to become visible after the LoadingView has been activated for 5 seconds.

What I need to do is created a custom class that has two methods: a way of converting a boolean to a visibility; and a way of converting a visibility to a visibility.

So I created a new folder in my tree called “Converters“. In here, I create a new class called “BooleanToVisiblityConverter“.  Here is what my tree now looks like:

  • ViewModels
    • ShellViewModel
    • LoadingViewModel
  • Views
    • ShellView
    • LoadingView
  • Converters
    • BooleanToVisibilityConverter

In my BooleanToVisibilityConverter class, I inherited from IValueConverter and added the necessary two methods. You can see the entire class below:

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Data;

namespace Project.Converters
{
    /// <summary>
    /// Contains the converter and convertback methods for the boolean to visibility conversions
    /// </summary>
    public sealed class BooleanToVisibilityConverter : IValueConverter
    {
        /// <summary>
        /// Used to convert a boolean to a visibility
        /// </summary>
        /// <param name="value">This is the boolean input</param>
        /// <param name="targetType"></param>
        /// <param name="parameter"></param>
        /// <param name="culture"></param>
        /// <returns>Returns a visibility</returns>
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (!(value is bool))
            {
                //If there is an issue with the input, return collapsed
                return Visibility.Collapsed;
            }
            return (bool)value ? Visibility.Visible : Visibility.Collapsed;
        }

        /// <summary>
        /// Used to take a visibility and returns a visibility
        /// </summary>
        /// <param name="value">This is the boolean input</param>
        /// <param name="targetType"></param>
        /// <param name="parameter"></param>
        /// <param name="culture"></param>
        /// <returns>Returns a visibility</returns>
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (!(value is Visibility))
            {
                //If there is an issue wtih the input, return collapsed
                return Visibility.Collapsed;
            }
            return (Visibility)value == Visibility.Visible;
        }
    }
}

Next, in my LoadingView, I added “ xmlns:sp=”clr-namespace:Project.Converters” so that the view could use the converter namespace. This is what my view dependancies look like:

<UserControl x:Class="Project.Views.MainView"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:cal="http://www.caliburnproject.org"
             xmlns:sp="clr-namespace:Project.Converters"
             xmlns:local="clr-namespace:Project.Views"
             mc:Ignorable="d" FontSize="14" FontFamily="/Project;component/Assets/Fonts/#Roboto"
             d:DesignHeight="550" d:DesignWidth="400">

I then added the binding to the visibility property of my button. You can see this below:

<Button Name="LoadingButton" Content="Press Me" Visibility="{Binding ButtonIsVisible, Converter={StaticResource BooleanConverter}, FallBackValue=Collapsed}"

This means that it will get its visibility value from the LoadingViewModel and if this fails, it will fall back to being collapsed.

We’re almost done. In the LoadingViewModel create a full property which will hold and change the value for the visibility. This needs to be named the same as the binding given in the LoadingView (i.e ButtonVisibility). You can see this below:

private bool _buttonIsVisible;

public bool ButtonIsVisible
{
    get {return _buttonIsVisible;
    set
    {
        if (value != _buttonIsVisible)
        {
            _buttonIsVisible = value;
            NotifyOfPropertyChange(() => ButtonIsVisible);
        }
    }
}

So now if you want the button to be visible, you can just update the ButtonIsVisible property in the LoadingViewModel. Here is an example below (Don’t actually do this):

public LoadingViewModel(){
    ButtonIsVisible = false;
    Task.Delay(5000);
    ButtonIsVisible = true;
}

I hope this helped you. Enjoy!