playtonedemo.java

人民邮电出版社的《J2ME手机开发入门》全部源代码

/*
 * PlayToneDemo.java
 *
 * Created on 2005年5月1日, 下午11:51
 */

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

/**
 *
 * @author  Liu Bin
 * @version
 */
public class PlayToneDemo extends MIDlet implements CommandListener {
    private Display display;
    
    Form form = new Form("音调播放演示");
    TextField tfNote = new TextField("请输入音调（0-127）", "49", 3,
            TextField.NUMERIC);
    TextField tfDuration = new TextField("请输入持续时间（毫秒）", "1000", 10,
            TextField.NUMERIC);
    Gauge gagVol = new Gauge("请选择音量", true, 100, 80);
    
    //命令按钮
    private Command cmdPlay = new Command("播放", Command.OK, 1);
    private Command cmdExit = new Command("退出", Command.STOP, 1);
    
    public PlayToneDemo() {
        gagVol.setLayout(Item.LAYOUT_EXPAND);
        
        form.append(tfNote);
        form.append(tfDuration);
        form.append(gagVol);
        form.addCommand(cmdPlay);
        form.addCommand(cmdExit);
        form.setCommandListener(this);
    }
    
    public void startApp() {
        display = Display.getDisplay(this);
        display.setCurrent(form);
    }
    
    public void pauseApp() {
    }
    
    public void destroyApp(boolean unconditional) {
    }
    
    /**
     * 命令按钮事件
     */
    public void commandAction(Command c, Displayable d) {
        String label = c.getLabel();
        if (label.equals("退出")) {
            this.notifyDestroyed();
        }
        
        if (label.equals("播放")) {
            //获得音调
            int note = Integer.parseInt(this.tfNote.getString());
            if ((note>=0) && (note<=127)) {
                //在音调值有效时继续处理
                int duration = Integer.parseInt(this.tfDuration.getString());
                int vol = this.gagVol.getValue();
                try {
                    javax.microedition.media.Manager.playTone(note, duration, vol);
                } catch (Exception e) {
                    System.out.println("播放声调发生异常：" + e.toString());
                }
            }
        }
    }
}