If you have built any video enabled application prior to WPF, you must be familiar with the Windows Media Player ActiveX control. The WPF library provides the MediaElement control that encapsulates Windows Media Player functionality.
The MediaElement tag in XAML allows you to play videos in XAML and WPF. The Source attribute of the tag takes the full path of the video. The following code snippet uses the MediaElement to display a video.
<MediaElement Name="VideoControl" Width="200" Height ="400"
Source="C:\Windows\System32\oobe\images\intro.wmv" >
</MediaElement>
The file can also be an Mpeg. The following code snippet plays a Mpeg video.
<MediaElement Name="VideoControl" Width="200" Height ="400"
Source="C:\TestV.MPG" >
</MediaElement>
The Width and Height attributes sets the width and height of the control respectively.
Setting MediaElement Properties Dynamically
You can also access the control programmatically and set its properties in your code. The following code snippet sets the MediaControls properties at run-time.
VideoControl.Volume = 100;
VideoControl.Width = 440;
VideoControl.Height = 280;
The Application
Now let’s build our video application. I want to create an application looks like Figure 1. As you can see from this figure, the Browse button allows me to browse a video file and Play, Pause, and Stop buttons plays, pauses, and stops the video.
Figure 1. Video enabled WPF application
The code listed in Listing 1 creates the user interface screen.
<TextBox Height="20" Margin="10,7,134,0" Name="MediaPathTextBox" VerticalAlignment="Top" ></TextBox>
<Button Height="20" HorizontalAlignment="Right" Margin="0,6,14,0" Name="BrowseButton"
VerticalAlignment="Top" Width="94" Click="BrowseClick">
Browse Media
</Button>
<MediaElement Canvas.Left="20" Canvas.Top ="40"
Name="VideoControl" LoadedBehavior="Manual" UnloadedBehavior="Stop" >
</MediaElement>
<Button Height="23" HorizontalAlignment="Left" Margin="15,0,0,13"
Name="PlayButton" VerticalAlignment="Bottom" Width="75"
Click="PlayClick">
Play</Button>
<Button Height="23" HorizontalAlignment="Left" Margin="103,0,0,13"
Name="PauseButton" VerticalAlignment="Bottom" Width="75"
Click="PauseClick">
Pause</Button>
<Button Height="23" Margin="191,0,186,13" Name="StopButton"
VerticalAlignment="Bottom" Click="StopClick">
Stop</Button>
</Grid>
Listing 1.
The code behind looks like Listing 2. As you can see from this code, on Windows1 constructor I sent the Volume, Width, and Height of the control.
The Browse button click event handler calls OpenFileDialog, which let us browse the files and sets the MediaPathTextBox.Text as the media file name.
The Play, Pause, and Stop button click handlers simply calls Play, Pause, and Stop methods of the MediaElement control.
public Window1()
{
InitializeComponent();
VideoControl.Volume = 100;
VideoControl.Width = 440;
VideoControl.Height = 280;
}
void BrowseClick(Object sender, EventArgs e)
{
OpenFileDialog openDlg = new OpenFileDialog();
openDlg.InitialDirectory = @"c:\";
openDlg.ShowDialog();
MediaPathTextBox.Text = openDlg.FileName;
}
void PlayClick(object sender, EventArgs e)
{
if (MediaPathTextBox.Text.Length <= 0)
{
System.Windows.Forms.MessageBox.Show("Enter a valid media file");
return;
}
VideoControl.Source = new Uri(MediaPathTextBox.Text);
VideoControl.Play();
}
void PauseClick(object sender, EventArgs e)
{
VideoControl.Pause();
}
void StopClick(object sender, EventArgs e)
{
VideoControl.Stop();
}
Listing 2.
Download the attached source code for more details.