volumecontroldemo.java

可以播放音乐,以及实现音乐播放的控制(包括控制音量,暂停等)

//import java.io.IOException;
//import java.io.InputStream;
//
import javax.microedition.lcdui.*;
//import javax.microedition.media.*;
//import javax.microedition.media.control.*;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;

public class VolumeControlDemo extends MIDlet 
                               implements CommandListener {
	private Display display;
	private Command exitCommand;
	private Command playCommand;
	private Command stopCommand;
	private Command pauseCommand;
	private Form f;
	private MusicCanvas musicCanvas;
	
	public VolumeControlDemo() {
		// TODO Auto-generated constructor stub
		display = Display.getDisplay(this);
		exitCommand = new Command("Exit", Command.EXIT, 2);
		playCommand = new Command("Play", Command.SCREEN, 2);
		stopCommand = new Command("Stop", Command.SCREEN, 2);
		pauseCommand = new Command("pause", Command.SCREEN, 2);
		f = new Form("正在播放");
		musicCanvas = new MusicCanvas();
		if (musicCanvas != null) {
			musicCanvas.addCommand(exitCommand);
			musicCanvas.addCommand(playCommand);
			musicCanvas.addCommand(stopCommand);
			musicCanvas.addCommand(pauseCommand);
			musicCanvas.setCommandListener(this);
		}
	}

	protected void destroyApp(boolean arg0) 
	                          throws MIDletStateChangeException {
		// TODO Auto-generated method stub
		musicCanvas.close();

	}

	protected void pauseApp() {
		// TODO Auto-generated method stub
	
	}

	protected void startApp() throws MIDletStateChangeException {
		// TODO Auto-generated method stub
		if (musicCanvas != null) {
			display.setCurrent(musicCanvas);
			musicCanvas.start();
		}
	}

	public void commandAction(Command c, Displayable s) {
		/*if语句也可以用以下的*/
//		String m = c.getLabel();
//		if (m.equals("Exit")) { 
//			try {
//				destroyApp(true);
//			} catch (MIDletStateChangeException e) {
//				// TODO Auto-generated catch block
//				e.printStackTrace();
//			}
//			notifyDestroyed();
//		}
		if (c == exitCommand) {
			musicCanvas.close();
			try {
				destroyApp(true);
			} catch (MIDletStateChangeException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			notifyDestroyed();
			
		} else if (c == playCommand) { 
			musicCanvas.playsong();
			f.setTicker(new Ticker("播放中"));
			display.setCurrent(musicCanvas);
		} else if (c == stopCommand) { 
			musicCanvas.close();
			display.setCurrent(musicCanvas);
		} else if (c == pauseCommand) {
			musicCanvas.pause();
		}
	}
}