ui_ex13.java

J2ME 无线通信技术应用开发源代码

// 程序名UI_Ex13.java
// 测试List类的SELECT_COMMAND
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class UI_Ex13 extends MIDlet implements CommandListener{
  private Display display; // 引用MIDlet的Display 对象
  private List mailList; //声明List类
  private Command cmdRead;
  private Command cmdReply;
  private Command cmdDelete;
  private Command cmdExit;
  private Image mailIcon,mailRead;
  private Alert alert;

  // MIDlet构造程序
  public UI_Ex13() {
    try {
      mailIcon = Image.createImage("/MailIcon.png");
      mailRead = Image.createImage("/MailRead.png");
    } catch (java.io.IOException e) {
      System.out.println("Error when get image!");
    }
    display = Display.getDisplay(this);
    alert = new Alert("读取邮件","",mailRead,AlertType.INFO);
    alert.setTimeout(Alert.FOREVER);
    cmdRead = new Command("Read",Command.SCREEN,1);
    cmdReply = new Command("Reply",Command.SCREEN,1);
    cmdDelete = new Command("Delete",Command.SCREEN,1);
    cmdExit = new Command("Exit",Command.SCREEN,1);
    mailList = new List("邮件列表", List.IMPLICIT);
    mailList.append("江城子",mailIcon);
    mailList.append("水调歌头",mailIcon);
    mailList.append("浣溪沙",mailIcon);
    mailList.append("定风波",mailIcon);
    mailList.addCommand(cmdRead);
    mailList.addCommand(cmdReply);
    mailList.addCommand(cmdDelete);
    mailList.addCommand(cmdExit);
    mailList.setCommandListener(this);
  }

  // 被应用程序管理器调用来启动MIDlet。
  public void startApp() {
    display.setCurrent(mailList);
  }

  // 一个必要的方法
  public void pauseApp() {
  }

  //一个必要的方法
  public void destroyApp(boolean unconditional) {
  }

  public void commandAction(Command c, Displayable d) {
    if (c == cmdRead || c == List.SELECT_COMMAND) {
      alert.setString("邮件:\n"+mailList.getString(mailList.getSelectedIndex()));
      display.setCurrent(alert,display.getCurrent());
    } else if (c == cmdDelete) {
      mailList.delete(mailList.getSelectedIndex());
    } else if (c == cmdExit) {
      destroyApp(false);
      notifyDestroyed();
    }
 }
}