flash.media.SoundChannel (Flex 3)

	Propriedade	Definido por
		constructor : Object A reference to the class object or constructor function for a given object instance.	Object
		leftPeak : Number [read-only] The current amplitude (volume) of the left channel, from 0 (silent) to 1 (full amplitude).	SoundChannel
		position : Number [read-only] When the sound is playing, the position property indicates the current point that is being played in the sound file.	SoundChannel
		prototype : Object [static] A reference to the prototype object of a class or function object.	Object
		rightPeak : Number [read-only] The current amplitude (volume) of the right channel, from 0 (silent) to 1 (full amplitude).	SoundChannel
		soundTransform : SoundTransform The SoundTransform object assigned to the sound channel.	SoundChannel

	Método	Definido por
		addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void Registers an event listener object with an EventDispatcher object so that the listener receives notification of an event.	EventDispatcher
		dispatchEvent(event:Event):Boolean Dispatches an event into the event flow.	EventDispatcher
		hasEventListener(type:String):Boolean Checks whether the EventDispatcher object has any listeners registered for a specific type of event.	EventDispatcher
		hasOwnProperty(name:String):Boolean Indicates whether an object has a specified property defined.	Object
		isPrototypeOf(theClass:Object):Boolean Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.	Object
		propertyIsEnumerable(name:String):Boolean Indicates whether the specified property exists and is enumerable.	Object
		removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void Removes a listener from the EventDispatcher object.	EventDispatcher
		setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Sets the availability of a dynamic property for loop operations.	Object
		stop():void Stops the sound playing in the channel.	SoundChannel
		toString():String Returns the string representation of the specified object.	Object
		valueOf():Object Returns the primitive value of the specified object.	Object
		willTrigger(type:String):Boolean Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type.	EventDispatcher

Descrição	Definido por
activate	Dispatched when Flash Player or the and AIR application gains operating system focus and becomes active.	EventDispatcher
deactivate	Dispatched when Flash Player loses operating system focus and is becoming inactive.	EventDispatcher
soundComplete	Dispatched when a sound has finished playing.	SoundChannel

Detalhes da propriedade

leftPeak

propriedade

leftPeak:Number [read-only]

The current amplitude (volume) of the left channel, from 0 (silent) to 1 (full amplitude).

Implementação
public function get leftPeak():Number

position

propriedade

position:Number [read-only]

When the sound is playing, the position property indicates the current point that is being played in the sound file. When the sound is stopped or paused, the position property indicates the last point that was played in the sound file.

A common use case is to save the value of the position property when the sound is stopped. You can resume the sound later by restarting it from that saved position.

Implementação
public function get position():Number

rightPeak

propriedade

rightPeak:Number [read-only]

The current amplitude (volume) of the right channel, from 0 (silent) to 1 (full amplitude).

Implementação
public function get rightPeak():Number

soundTransform

propriedade

soundTransform:SoundTransform [read-write]

The SoundTransform object assigned to the sound channel. A SoundTransform object includes properties for setting volume, panning, left speaker assignment, and right speaker assignment.

Implementação
public function get soundTransform():SoundTransform
public function set soundTransform(value:SoundTransform):void

Veja também

SoundTransform

Detalhes do método

stop

()

método

public function stop():void

Stops the sound playing in the channel.

Exemplo

In the following exemplo, the user can click a button to pause and replay a sound file.

In the constructor, the sound file is loaded. (Here, it is assumed that the file is in the same directory as the SWF file.) A text field is used as a button for the user to play or pause the sound. When the user clicks on the button text field, the clickHandler() method is invoked.

In the clickHandler() method, the first time the user clicks on the text field, the sound is set to play and assigned to a sound channel. Next, when the user clicks on the text field to pause, the sound will stop playing. The sound channel's position property records the position of the sound at the time it was stopped and is used to resume the sound starting at that position, once the user clicks on text field to start playing again. Note that each time the Sound.play() method is called, a new SoundChannel object is created and assigned to the channel variable. The Sound object needs to be assigned to a SoundChannel object in order to use the sound channel's stop() method to pause the sound.


package {
    import flash.display.Sprite;
    import flash.media.Sound;
    import flash.media.SoundChannel;
    import flash.net.URLLoader;
    import flash.net.URLRequest;
    import flash.text.TextField;
    import flash.events.MouseEvent;
    import flash.text.TextFieldAutoSize;
            
    public class SoundChannel_stopExample extends Sprite {
        private var snd:Sound = new Sound();
        private var channel:SoundChannel = new SoundChannel();
        private var button:TextField = new TextField();

        public function SoundChannel_stopExample() {
            var req:URLRequest = new URLRequest("MySound.mp3");
            snd.load(req);
            
            button.x = 10;
            button.y = 10;
            button.text = "PLAY";
            button.border = true;
            button.background = true;
            button.selectable = false;
            button.autoSize = TextFieldAutoSize.CENTER;

            button.addEventListener(MouseEvent.CLICK, clickHandler);

            this.addChild(button);
        }

        private function clickHandler(e:MouseEvent):void {
            var pausePosition:int = channel.position;

            if(button.text == "PLAY") {
                channel = snd.play(pausePosition);
                button.text = "PAUSE";
            } 
            else {
                channel.stop();
                button.text = "PLAY";
            }
        }
    }
}

Detalhes do evento

soundComplete

Evento

Event Object Type: flash.events.Event
Event.type property = flash.events.Event.SOUND_COMPLETE

Dispatched when a sound has finished playing.

The Event.SOUND_COMPLETE constant defines the value of the type property of a soundComplete event object.

This event has the following properties:

Propriedade	Valor
`bubbles`	`false`
`cancelable`	`false`; there is no default behavior to cancel.
`currentTarget`	The object that is actively processing the Event object with an event listener.
`target`	The Sound object on which a sound has finished playing.

Exemplo

In the following exemplo, the user selects songs from a playlist and then clicks on "play" to play the song in the order selected.

In the constructor, a text field is defined that holds the song list and a line for selecting to play. (Normally, buttons will be used for play and list boxes for a song list.) A text format object has been defined to change the format of the song lines to italic once selected. When the user clicks on the text field, the clickHandler() method is invoked.

In the clickHandler() method, the getLineIndexAtPoint() of the text field object returns the index of line where the user clicked. Using the line index, the getLineText() method gets the content of the text. The if statement checks if the user has selected to play or to add a song to the play list. If a user has selected to play and a song has been selected, then the event listener for mouse click is removed and the playNext() method is called to begin playing the songs. If the user has selected a song title, then the content of the line is added to the songList array and the format of the line is set to italic.

The method playNext() iterates through the array list to load and play each song. The song is also assigned to a sound channel. An event listener for the sound channel is added to respond when the song is finished playing and the Event.SOUND_COMPLETE event is dispatched. The soundCompleteHandler() method then invoke the playNext() method to play the next song. This process continues until all the songs listed in the array are finished playing.

package {
    import flash.display.Sprite;
    import flash.media.Sound;
    import flash.media.SoundChannel;
    import flash.text.TextField;
    import flash.text.TextFieldAutoSize;
    import flash.events.MouseEvent;
    import flash.text.TextFormat;
    import flash.net.URLRequest;
    import flash.events.Event;
    import flash.events.IOErrorEvent;

    public class SoundChannel_event_soundCompleteExample extends Sprite {
        private var channel:SoundChannel = new SoundChannel();
        private var songList:Array = new Array();
        private var listTextField:TextField = new TextField();
        private var songFormat:TextFormat = new TextFormat();
        private var arrayIndex:int = 0;
        private var songSelected:Boolean = false;
        
        public function SoundChannel_event_soundCompleteExample() {
            
            listTextField.autoSize = TextFieldAutoSize.LEFT;
            listTextField.border = true
            listTextField.background = true;
            listTextField.text = "Song1.mp3\n" + "Song2.mp3\n" 
                                + "Song3.mp3\n" + "Song4.mp3\n" + "PLAY";
        
            songFormat.italic = true;
 
            listTextField.addEventListener(MouseEvent.CLICK, clickHandler);
                        
            addChild(listTextField);
        }
        
        private function clickHandler(e:MouseEvent):void {
            var index:int = listTextField.getLineIndexAtPoint(e.localX, e.localY);
            var line:String = listTextField.getLineText(index);
            var firstIndex:uint = listTextField.getLineOffset(index);
            var playLine:uint = listTextField.numLines - 1;

                if((index == playLine) && (songSelected == true)) {
                    listTextField.removeEventListener(MouseEvent.CLICK, clickHandler);
                    playNext();       

                } else if (index != playLine) {
                     songList.push(line.substr(0, (line.length - 1)));
                     listTextField.setTextFormat(songFormat, firstIndex, 
                                (firstIndex + listTextField.getLineLength(index)));     
                    songSelected = true;
                 }
        }

        private function playNext():void {
 
             if(arrayIndex < songList.length) {
                var snd:Sound = new Sound();
                snd.load(new URLRequest(songList[arrayIndex]));
                channel = snd.play();
                
                channel.addEventListener(Event.SOUND_COMPLETE, soundCompleteHandler);
                arrayIndex++;
 
            } else {
                songSelected = false;
                    
                while(arrayIndex > 0) {
                    songList.pop();
                    arrayIndex--;
                }
            }
        }    

        private function soundCompleteHandler(e:Event):void {
            playNext();
        }

        private function errorHandler(errorEvent:IOErrorEvent):void {
            trace(errorEvent.text);
        }
    }
}

Exemplos How to use examples

SoundChannelExample.as

The following exemplo loads an MP3 file, plays it, and displays information about sound events that take place as the MP3 file is loaded and played. A Timer object provides updated information about the position of the playhead every 50 milliseconds. To run this exemplo, place a file named MySound.mp3 in the same directory as your SWF file.

package {
    import flash.display.Sprite;
    import flash.events.*;
    import flash.media.Sound;
    import flash.media.SoundChannel;
    import flash.net.URLRequest;
    import flash.utils.Timer;

    public class SoundChannelExample extends Sprite {
        private var url:String = "MySound.mp3";
        private var soundFactory:Sound;
        private var channel:SoundChannel;
        private var positionTimer:Timer;

        public function SoundChannelExample() {
            var request:URLRequest = new URLRequest(url);
            soundFactory = new Sound();
            soundFactory.addEventListener(Event.COMPLETE, completeHandler);
            soundFactory.addEventListener(Event.ID3, id3Handler);
            soundFactory.addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler);
            soundFactory.addEventListener(ProgressEvent.PROGRESS, progressHandler);
            soundFactory.load(request);

            channel = soundFactory.play();
            channel.addEventListener(Event.SOUND_COMPLETE, soundCompleteHandler);

            positionTimer = new Timer(50);
            positionTimer.addEventListener(TimerEvent.TIMER, positionTimerHandler);
            positionTimer.start();
        }
        

        private function positionTimerHandler(event:TimerEvent):void {
            trace("positionTimerHandler: " + channel.position.toFixed(2));
        }

        private function completeHandler(event:Event):void {
            trace("completeHandler: " + event);
        }

        private function id3Handler(event:Event):void {
            trace("id3Handler: " + event);
        }

        private function ioErrorHandler(event:Event):void {
            trace("ioErrorHandler: " + event);
            positionTimer.stop();       
        }

        private function progressHandler(event:ProgressEvent):void {
            trace("progressHandler: " + event);
        }

        private function soundCompleteHandler(event:Event):void {
            trace("soundCompleteHandler: " + event);
            positionTimer.stop();
        }
    }
}

Flex 3 - Referência da Linguagem	All Packages \| All Classes \| Language Elements \| Index \| Appendixes \| Conventions \| Frames No Frames
SoundChannel	Propriedades \| Métodos \| Eventos \| Exemplos

Pacote	flash.media
Classe	public final class SoundChannel
Herança	SoundChannel EventDispatcher Object