volumecontroldemo.java

J2ME中音量的控制

/*
 * 音量调整例子
 */

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class VolumeControlDemo extends MIDlet implements CommandListener {
	private Display display; 

	private Command exitCommand;

	private Command playCommand;

	private Command stopCommand; 

	private MusicCanvas musicCanvas; 

	public VolumeControlDemo() {
		display = Display.getDisplay(this);
		exitCommand = new Command("Exit", Command.EXIT, 1);
		playCommand = new Command("Play", Command.SCREEN, 2);
		stopCommand = new Command("Stop", Command.SCREEN, 2);
		
		if ((musicCanvas = new MusicCanvas()) != null) {
			musicCanvas.addCommand(exitCommand);
			musicCanvas.addCommand(playCommand);
			musicCanvas.addCommand(stopCommand);
			musicCanvas.setCommandListener(this);
		}
	}

	public void startApp() {
		if (musicCanvas != null) {
			display.setCurrent(musicCanvas);
			musicCanvas.start();
		}
	}

	public void pauseApp() {
	}

	public void destroyApp(boolean unconditional) {
		musicCanvas.stop();
	}

	public void commandAction(Command c, Displayable s) {
		if (c == exitCommand)
		{
			musicCanvas.stop();

			destroyApp(true);
			notifyDestroyed();
		} else if (c == playCommand) //播放Wav文件
		{
			musicCanvas.playsong();
		} else if (c == stopCommand) //停止播放
		{
			musicCanvas.stop();
		}
	}
}