Using embedded MediaElement controls to play videos in WPF / MVVM

Essentially the same as these instructions, but using a purely MVVM approach and without the additional stop / start / pause etc buttons - the application just 'sees' the MP4 media file it needs to play and plays it upon startup. Step 1: Create a new WPF Application Step 2: Create the Main Window ViewModel classes Add the following classes to your project: MainWindowViewModel.cs [code language="csharp"] namespace MediaElement { public class MainWindowViewModel : BaseViewModel { private string _url; public MainWindowViewModel() { Url = "E:\\temp\\SampleMp4File.mp4"; } public string Url { get { return _url; } set { if (_url == value) return; _url = value; OnPropertyChanged("Url"); } } } } [/code] BaseViewModel.cs [code language="csharp"] using System; using System.ComponentModel; using System.Diagnostics; namespace MediaElement { public abstract class BaseViewModel : INotifyPropertyChanged { #region INotifyPropertyChanged Members public event PropertyChangedEventHandler PropertyChanged; #endregion protected void OnPropertyChanged(string propertyName) { VerifyPropertyName(propertyName); var handler = PropertyChanged; if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName)); } protected void OnPropertyChanged(int propertyValue) { VerifyPropertyName(propertyValue); var handler = PropertyChanged; if (handler != null) handler(this, new PropertyChangedEventArgs(propertyValue.ToString())); } [Conditional("DEBUG")] private void VerifyPropertyName(string propertyName) { if (TypeDescriptor.GetProperties(this)[propertyName] == null) throw new ArgumentNullException(GetType().Name + " does not contain property: " + propertyName); } [Conditional("DEBUG")] private void VerifyPropertyName(int propertyValue) { if (TypeDescriptor.GetProperties(this)[propertyValue] == null) throw new ArgumentNullException(GetType().Name + " does not contain property: " + propertyValue); } } } [/code] Step 3: Add infrastructure to handle the even raising etc. Just add the following classes to your project: EventArgs.cs [code language="csharp"] using System; namespace MediaElement { public class EventArgs<T> : EventArgs { public EventArgs(T value) { Value = value; } public T Value { get; private set; } } } [/code] EventRaiser.cs [code language="csharp"] using System; namespace MediaElement { public static class EventRaiser { public static void Raise(this EventHandler handler, object sender) { if (handler != null) handler(sender, EventArgs.Empty); } public static void Raise<T>(this EventHandler<EventArgs<T>> handler, object sender, T value) { if (handler != null) handler(sender, new EventArgs<T>(value)); } public static void Raise<T>(this EventHandler<T> handler, object sender, T value) where T : EventArgs { if (handler != null) handler(sender, value); } public static void Raise<T>(this EventHandler<EventArgs<T>> handler, object sender, EventArgs<T> value) { if (handler != null) handler(sender, value); } } } [/code] RelayCommand.cs [code language="csharp"] using System; using System.Windows.Input; namespace MediaElement { public class RelayCommand<T> : ICommand { private readonly Predicate<T> _canExecute; private readonly Action<T> _execute; public RelayCommand(Action<T> execute) : this(execute, null) { _execute = execute; } public RelayCommand(Action<T> execute, Predicate<T> canExecute) { if (execute == null) throw new ArgumentNullException("execute"); _execute = execute; _canExecute = canExecute; } public bool CanExecute(object parameter) { return (_canExecute == null) || _canExecute((T) parameter); } public void Execute(object parameter) { _execute((T) parameter); } public event EventHandler CanExecuteChanged { add { CommandManager.RequerySuggested += value; } remove { CommandManager.RequerySuggested -= value; } } } public class RelayCommand : ICommand { private readonly Predicate<object> _canExecute; private readonly Action<object> _execute; public RelayCommand(Action<object> execute) : this(execute, null) { _execute = execute; } public RelayCommand(Action<object> execute, Predicate<object> canExecute) { if (execute == null) throw new ArgumentNullException("execute"); _execute = execute; _canExecute = canExecute; } public bool CanExecute(object parameter) { return (_canExecute == null) || _canExecute(parameter); } public void Execute(object parameter) { _execute(parameter); } // Ensures WPF commanding infrastructure asks all RelayCommand objects whether their // associated views should be enabled whenever a command is invoked public event EventHandler CanExecuteChanged { add { CommandManager.RequerySuggested += value; CanExecuteChangedInternal += value; } remove { CommandManager.RequerySuggested -= value; CanExecuteChangedInternal -= value; } } private event EventHandler CanExecuteChangedInternal; public void RaiseCanExecuteChanged() { CanExecuteChangedInternal.Raise(this); } } } [/code] Step 4: Embed the MediaElement control in your MainWindow.xaml [code language="xml"] <Window x:Class="MediaElement.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:MediaElement" mc:Ignorable="d" Title="MainWindow" Height="350" Width="525"> <Window.DataContext> <local:MainWindowViewModel/> </Window.DataContext> <Grid> <Grid.RowDefinitions> <RowDefinition Height="320*"/> </Grid.RowDefinitions> <MediaElement Grid.RowSpan="1" Source="{Binding Url}" LoadedBehavior="Play"/> </Grid> </Window> [/code] Step 5: Run it!