ui_ex10.java

J2ME 无线通信技术应用开发源代码

// 程序名UI_Ex10.java
// 测试Alert对象
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class UI_Ex10 extends MIDlet implements CommandListener {
  private Display display; // 引用MIDlet的Display 对象
  private Alert alert; // 设置一个告警对象
  private TextBox textBox;
  private Command cmdExit; // 设定按钮用于退出MIDlet
  private Command cmdAlert; // 设定按钮用于退出MIDlet
  //private Command cmdinAlert;//为Alert添加一个Command对象

  // MIDlet构造程序
  public UI_Ex10() {
    display = Display.getDisplay(this);
    cmdExit = new Command("Exit", Command.SCREEN, 1);
    cmdAlert = new Command("Alert", Command.SCREEN, 1);
    //cmdinAlert = new Command("inAlert", Command.EXIT, 1);
    textBox = new TextBox("Test Alert","Press \"Alert\" , and get a alert!",50,0);
    textBox.addCommand(cmdExit);
    textBox.addCommand(cmdAlert);
    textBox.setCommandListener(this);
    alert = new Alert("alert!"," Is this alert simple?",null,AlertType.INFO);
    alert.setTimeout(Alert.FOREVER);
    /*
    try {
      Image img = Image.createImage("/Duke.png");
      alert.setImage(img);
    } catch (java.io.IOException e) {
      System.out.println("Error when set image!");
    }
    */
    /*
    try {
      alert.addCommand(cmdinAlert);
    } catch (java.lang.IllegalStateException e) {
      System.out.println(e.toString());
    }
    */
  }

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

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

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

  //检查一下是否选择了退出命令
  public void commandAction(Command c, Displayable d) {
    if (c == cmdAlert) {
      display.setCurrent(alert,display.getCurrent());
    }
    if (c == cmdExit) {
      destroyApp(false);
      notifyDestroyed();
    }
 }
}