CurrentStateChanged Event
Occurs when the value of the CurrentState property changes.
| XAML |
<object CurrentStateChanged="eventhandlerFunction" .../>
|
| Scripting |
[token = ]object.AddEventListener("CurrentStateChanged", eventhandlerFunction)
|
AddEventListener Parameters
| token | integer A token that is returned from the function, which you can optionally retain as a variable. If you intend to call RemoveEventListener to remove the handler, you will need this token. |
| eventhandlerFunction | object The name of your event handler function as it is defined in script. When used as an AddEventListener parameter, quotes around the function name are not required. See Remarks. |
Event Handler Parameters
| sender | object Identifies the object that invoked the event. |
| eventArgs | object This parameter is always set to null. |
Remarks
You can also add handlers in script using a quoted string for the event handler name:
object.AddEventListener("CurrentStateChanged", "eventhandlerFunction")
This syntax also returns a token; however, the token is not an absolute requirement for removing the handler, in cases where the handler was added by using a quoted string. For details, see RemoveEventListener.
It is possible for this event to be raised multiple times before its event handlers are executed.
Although this event occurs when the CurrentState becomes invalid, that does not necessarily mean that the CurrentState property has a new value. For example, the CurrentState property might have switched from Playing to Buffering and back to Playing so rapidly that only a single CurrentStateChanged event was raised, in which case the property will not appear to have changed values. Also, your application should not assume an order in which the events occur, particularly for the transient states such as "Buffering". One of the transient states may have been skipped over in event reporting because it happened so rapidly.
Examples
The following example demonstrates one way to display the CurrentState of a MediaElement. It creates a MediaElement and several buttons for controlling media playback. To display the current state of the MediaElement, the example registers for the CurrentStateChanged event and uses an event handler to update a TextBlock.
| XAML |
|---|
<Canvas
xmlns="https://schemas.microsoft.com/client/2007"
xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
Width="300" Height="300">
<MediaElement
x:Name="media"
Source="xbox.wmv"
CurrentStateChanged="media_state_changed"
Width="300" Height="300"/>
<!-- Stops media playback.-->
<Canvas MouseLeftButtonDown="media_stop"
Canvas.Left="10" Canvas.Top="265">
<Rectangle Stroke="Black"
Height="30" Width="55" RadiusX="5" RadiusY="5">
<Rectangle.Fill>
<RadialGradientBrush GradientOrigin="0.75,0.25">
<GradientStop Color="Orange" Offset="0.0" />
<GradientStop Color="Red" Offset="1.0" />
</RadialGradientBrush>
</Rectangle.Fill>
</Rectangle>
<TextBlock Canvas.Left="5" Canvas.Top="5">stop</TextBlock>
</Canvas>
<!-- Pauses media playback. -->
<Canvas MouseLeftButtonDown="media_pause"
Canvas.Left="70" Canvas.Top="265">
<Rectangle Stroke="Black"
Height="30" Width="55" RadiusX="5" RadiusY="5">
<Rectangle.Fill>
<RadialGradientBrush GradientOrigin="0.75,0.25">
<GradientStop Color="Yellow" Offset="0.0" />
<GradientStop Color="Orange" Offset="1.0" />
</RadialGradientBrush>
</Rectangle.Fill>
</Rectangle>
<TextBlock Canvas.Left="5" Canvas.Top="5">pause</TextBlock>
</Canvas>
<!-- Begins media playback. -->
<Canvas MouseLeftButtonDown="media_begin"
Canvas.Left="130" Canvas.Top="265">
<Rectangle Stroke="Black" RadiusX="5" RadiusY="5"
Height="30" Width="55">
<Rectangle.Fill>
<RadialGradientBrush GradientOrigin="0.75,0.25">
<GradientStop Color="LimeGreen" Offset="0.0" />
<GradientStop Color="Green" Offset="1.0" />
</RadialGradientBrush>
</Rectangle.Fill>
</Rectangle>
<TextBlock Canvas.Left="5" Canvas.Top="5">play</TextBlock>
</Canvas>
<TextBlock
Canvas.Left="190" Canvas.Top="265"
FontSize="12">CurrentState:</TextBlock>
<TextBlock
x:Name="mediaStateTextBlock"
Canvas.Left="190" Canvas.Top="280"
FontSize="12"></TextBlock>
</Canvas>
|
| JavaScript |
|---|
function media_stop(sender, args)
{
sender.findName("media").stop();
}
function media_pause(sender, args)
{
sender.findName("media").pause();
}
function media_begin(sender, args)
{
sender.findName("media").play();
}
function media_state_changed(sender, args)
{
var mediaStateTextBlock =
sender.findName("mediaStateTextBlock");
var media = sender.findName("media");
mediaStateTextBlock.Text = media.CurrentState;
}
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