itemstatelistener.java~1~

J2ME高级用户界面的学习代码

//ItemStateListener.java

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

public class ItemStateListener extends MIDlet implements CommandListener
{
  private Command cmdExit =  new Command("Exit",Command.EXIT,1);
  private Form mForm;
  private TextField mTextField;
  private StringItem mStringItem;

  public ItemStateListener()
  {
    mForm = new Form("ItemStateListener Demostation");
    mTextField =  new TextField("Input"," ",50,TextField.ANY);
    mStringItem = new StringItem("The input is:","");
    mForm.append(mTextField);
    mForm.append(mStringItem);
    ItemStateListener listener = new ItemStateListener()
    {
      public void itemStateChanged(Item mItem)
      {
        if(mItem == mTextField)
        {
          int len = mTextField.size();
          char[] charArray = new char[len];
          mTextField.getChars(charArray);
          mStringItem.setText(new String(charArray));
        }
      }
    };
    mForm.setItemStateListener(listener);
    mForm.addCommand(cmdExit);
    mForm.setCommandListener(this);
  }

  public void startApp()
  {
    Display.getDisplay(this).setCurrent(mForm);
  }

  public void commandAction(Command c,Displayable d)
  {
    if(cmdExit == c)
    {
      destroyApp(false);
      notifyDestroyed();
    }
  }

  public void destroyApp(boolean unconditional){}
  public void pauseApp(){}
}