Media Player: come svilupparne uno in C#

Per cominciare bisogna creare la nostra finestra grafica:

1. Bisogna importare l’oggetto MediaElement all’interno della nostra finestra: le dimensioni sono a vostra discrezione e piacere poiché la finestra ha solitamente una misura standard iniziale di 500×300
2. Il passo successivo è creare dei comandi che permettano all’utente di stoppare e riprodurre il file, nonché metterlo in pausa.
   Noi abbiamo deciso di sfruttare l’oggetto ToolBar che è un tipo di oggetto che permette l’inserimento di pulsanti, immagini e altri tipi di oggetti che arricchiscono la GUI.
3. Successivamente andremo ad aggiungere la barra di stato dove ci saranno i controlli del volume e uno Slider per poter mandare avanti e indietro il video.
4. Infine bisogna aggiungere i vari eventi per permettere all’applicazione di funzionare: XAML della MainWindow:
   

   <Window x:Class="WpfApp2.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:local="clr-namespace:WpfApp2"
    mc:Ignorable="d"
    Title="Media Player" Height="350" Width="525">
    <Window.CommandBindings>
    <CommandBinding Command="ApplicationCommands.Open" CanExecute="Open_CanExecute" Executed="Open_Executed" />
    <CommandBinding Command="MediaCommands.Play" CanExecute="Play_CanExecute" Executed="Play_Executed" />
    <CommandBinding Command="MediaCommands.Pause" CanExecute="Pause_CanExecute" Executed="Pause_Executed" />
    <CommandBinding Command="MediaCommands.Stop" CanExecute="Stop_CanExecute" Executed="Stop_Executed" />
    </Window.CommandBindings>
    <Grid MouseWheel="Grid_MouseWheel">
    <Grid.RowDefinitions>
    <RowDefinition Height="Auto" />
    <RowDefinition Height="*" />
    <RowDefinition Height="Auto" />
    </Grid.RowDefinitions>
    <ToolBar>
    <Button Command="ApplicationCommands.Open">
    <Image Source="images/1493679837_icon-folder.png" Height="26" />
    </Button>
    <Separator />
    <Button Command="MediaCommands.Play">
    <Image Source="images/1493679955_23_Play.png" Height="26" />
    </Button>
    <Button Command="MediaCommands.Pause">
    <Image Source="images/1493679959_25_Pause.png" Height="26" />
    </Button>
    <Button Command="MediaCommands.Stop">
    <Image Source="images/1493679953_24_Stop.png" Height="26" />
    </Button>
    </ToolBar>
   
   <MediaElement Name="mePlayer" Grid.Row="1" LoadedBehavior="Manual" Stretch="Uniform" />
   
   <StatusBar Grid.Row="2">
    <StatusBar.ItemsPanel>
    <ItemsPanelTemplate>
    <Grid>
    <Grid.ColumnDefinitions>
    <ColumnDefinition Width="Auto" />
    <ColumnDefinition Width="*" />
    <ColumnDefinition Width="Auto" />
    </Grid.ColumnDefinitions>
    </Grid>
    </ItemsPanelTemplate>
    </StatusBar.ItemsPanel>
    <StatusBarItem>
    <TextBlock Name="lblProgressStatus">00:00:00</TextBlock>
    </StatusBarItem>
    <StatusBarItem Grid.Column="1" HorizontalContentAlignment="Stretch">
    <Slider Name="sliProgress" Thumb.DragStarted="sliProgress_DragStarted" Thumb.DragCompleted="sliProgress_DragCompleted" ValueChanged="sliProgress_ValueChanged" />
    </StatusBarItem>
    <StatusBarItem Grid.Column="2">
    <ProgressBar Name="pbVolume" Width="50" Height="12" Maximum="1" Value="{Binding ElementName=mePlayer, Path=Volume}" />
    </StatusBarItem>
    </StatusBar>
    </Grid>
   </Window>

   CodeBehind Microsoft Visual C#:

   using Microsoft.Win32;
   using System;
   using System.Windows;
   using System.Windows.Controls.Primitives;
   using System.Windows.Input;
   using System.Windows.Threading;
   
   namespace WpfApp2
   {
    /// <summary>
    /// Logica di interazione per MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
    private string titolo = "Media Player";
    private bool mediaPlayerIsPlaying = false;
    private bool userIsDraggingSlider = false;
    public MainWindow()
    {
    InitializeComponent();
   
   DispatcherTimer timer = new DispatcherTimer();
    timer.Interval = TimeSpan.FromSeconds(1);
    timer.Tick += timer_Tick;
    timer.Start();
    }
   
   private void timer_Tick(object sender, EventArgs e)
    {
    if ((mePlayer.Source != null) && (mePlayer.NaturalDuration.HasTimeSpan) && (!userIsDraggingSlider))
    {
    sliProgress.Minimum = 0;
    sliProgress.Maximum = mePlayer.NaturalDuration.TimeSpan.TotalSeconds;
    sliProgress.Value = mePlayer.Position.TotalSeconds;
    }
    }
   
   private void Open_CanExecute(object sender, CanExecuteRoutedEventArgs e)
    {
    e.CanExecute = true;
    }
   
   private void Open_Executed(object sender, ExecutedRoutedEventArgs e)
    {
    
    OpenFileDialog openFileDialog = new OpenFileDialog();
    openFileDialog.Filter = "File audio (*.mp3;*.mpg;*.mpeg)|*.mp3;*.mpg;*.mpeg|File video (*.mp4;*.avi;*.mov)|*.mp4;*.avi;*.mov|All files (*.*)|*.*";
    if (openFileDialog.ShowDialog() == true)
    {
    mePlayer.Source = new Uri(openFileDialog.FileName);
    Title = titolo + " - " + openFileDialog.SafeFileName;
    }
    }
   
   private void Play_CanExecute(object sender, CanExecuteRoutedEventArgs e)
    {
    e.CanExecute = (mePlayer != null) && (mePlayer.Source != null);
    }
   
   private void Play_Executed(object sender, ExecutedRoutedEventArgs e)
    {
    mePlayer.Play();
    mediaPlayerIsPlaying = true;
    }
   
   private void Pause_CanExecute(object sender, CanExecuteRoutedEventArgs e)
    {
    e.CanExecute = mediaPlayerIsPlaying;
    }
   
   private void Pause_Executed(object sender, ExecutedRoutedEventArgs e)
    {
    mePlayer.Pause();
    }
   
   private void Stop_CanExecute(object sender, CanExecuteRoutedEventArgs e)
    {
    e.CanExecute = mediaPlayerIsPlaying;
    }
   
   private void Stop_Executed(object sender, ExecutedRoutedEventArgs e)
    {
    mePlayer.Stop();
    mediaPlayerIsPlaying = false;
    }
   
   private void sliProgress_DragStarted(object sender, DragStartedEventArgs e)
    {
    userIsDraggingSlider = true;
    }
   
   private void sliProgress_DragCompleted(object sender, DragCompletedEventArgs e)
    {
    userIsDraggingSlider = false;
    mePlayer.Position = TimeSpan.FromSeconds(sliProgress.Value);
    }
   
   private void sliProgress_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
    {
    lblProgressStatus.Text = TimeSpan.FromSeconds(sliProgress.Value).ToString(@"hh\:mm\:ss");
    }
   
   private void Grid_MouseWheel(object sender, MouseWheelEventArgs e)
    {
    mePlayer.Volume += (e.Delta > 0) ? 0.1 : -0.1;
    }
    }
   }

Eseguibile disponibile per il download: WpfApp2