emailmidlet.java

J2ME程序设计实例教程的源码

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

/**
 * 该类是应用程序的主类，实现了生命周期的控制方法。
 */
public class EMailMIDlet extends MIDlet implements CommandListener {
    private Display display;
    private Alert alert;
    
    private String[] menuItems = {"发送邮件", "配置邮件服务器"};
    private List menu;  //应用程序主菜单
    
    private SendForm sendForm;
    
    private Command cmdExit = new Command("退出", Command.EXIT, 1);
    private Command cmdSelect = new Command("选择", Command.ITEM, 1);
    private Command cmdBack = new Command("返回", Command.BACK, 1);
    private Command cmdSend = new Command("发送", Command.SCREEN, 2);
    private Command cmdSave = new Command("保存", Command.OK, 1);
    
    public EMailMIDlet() {
        display = Display.getDisplay(this);
        menu = new List("移动电子邮件", Choice.IMPLICIT, menuItems, null);
        menu.setSelectCommand(cmdSelect);
        menu.addCommand(cmdExit);
        menu.setCommandListener(this);
    }
    
    public void startApp() {
        EMailConfig config = EMailConfig.getInstance();
        if(config == null) {
            ConfigForm configForm = new ConfigForm(this, null);
            display.setCurrent(configForm);
        }
        else {
            display.setCurrent(menu);
        }
    }
    
    public void pauseApp() {
        //
    }
    
    public void destroyApp(boolean unconditional) {
        //
    }
    
    
    public void commandAction(Command cmd, Displayable d) {
        if(cmd == cmdSelect) {  //选择菜单项
            switch(menu.getSelectedIndex()) {
                case 0: {   //显示发送邮件界面
                    if(sendForm == null) {
                        sendForm = new SendForm(this);
                    }
                    sendForm.clear();
                    display.setCurrent(sendForm);
                    break;
                }
                case 1: {   //显示配置界面
                    EMailConfig config = EMailConfig.getInstance();
                    ConfigForm configForm = new ConfigForm(this, config);
                    display.setCurrent(configForm);
                    break;
                }
            }
        }
        else if(cmd == cmdExit) {
            notifyDestroyed();
        }
    }
    
    //
    public void showAlert(String title, String msg) {
        if(alert == null) {
            alert = new Alert("", "", null, AlertType.INFO);
            alert.setTimeout(3000);
        }
        alert.setTitle(title);
        alert.setString(msg);
        display.setCurrent(alert, display.getCurrent());
    }
    
    public void backToMenu() {
        display.setCurrent(menu);
    }
}