MediaElement.BufferingProgressChanged Event
Silverlight
Occurs when the BufferingProgress property changes.
Namespace: System.Windows.Controls
Assembly: System.Windows (in System.Windows.dll)
For Silverlight for Windows Phone, buffering will pause for VC-1 content if the stream is paused.
The BufferingProgressChanged event typically occurs multiple times during a download. The event will occur when the BufferingProgress value increases by 0.05 or more, compared to the last time the event was raised, and also when the value reaches 1.0.
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.