J2ME中使用TextField实现表单界面代码实战

本例主要借助Form和TextBox显示。

代码如下：

/**
 * @作者 Jcuckoo
 * @创建日期 2008-11-18
 * @版本 V 1.0
 */
public class TextFieldMIDlet extends MIDlet implements CommandListener{
 //声名
 private Display display;
 
 private Form myform;
 private TextField userName;
 private TextField userPwd;
 private TextField email;
 private TextField number;
 private TextField value;
 private TextField telnum;
 
 private TextBox showMessage;
 private Command saveCommand;
 private Command backCommand;
 private Command exitCommand;
 
 public TextFieldMIDlet() {
  display=Display.getDisplay(this);
  myform=new Form("TextField实例测试");
  
  userName=new TextField("姓名：","",20,TextField.ANY);
  userPwd=new TextField("密码：","",20,TextField.PASSWORD);
  email=new TextField("Email：","",20,TextField.EMAILADDR);
  number=new TextField("数字字符串：","",20,TextField.NUMERIC);
  value=new TextField("数值：","",20,TextField.DECIMAL);
  telnum=new TextField("电话号码：","",20,TextField.PHONENUMBER);
  
  saveCommand=new Command("保存",Command.SCREEN,1);
  backCommand=new Command("返回",Command.BACK,1);
  exitCommand=new Command("退出",Command.EXIT,1);
  
  myform.append(userName);
  myform.append(userPwd);
  myform.append(email);
  myform.append(number);
  myform.append(value);
  myform.append(telnum);
  myform.addCommand(saveCommand);
  myform.addCommand(exitCommand);
  myform.setCommandListener(this);
  
  showMessage=new TextBox("你输入的信息为：","",200,TextField.ANY);
  showMessage.addCommand(backCommand);
  showMessage.addCommand(exitCommand);
  showMessage.setCommandListener(this);
 }
 protected void destroyApp(boolean arg0){
 }
 protected void pauseApp() {
 }
 protected void startApp() throws MIDletStateChangeException {
  display.setCurrent(myform);
 }
 public void commandAction(Command c, Displayable d) {
  if(c==saveCommand){
   //方法一：使用String测试
   /*
   String tmp="";
   tmp+=userName.getLabel()+userName.getString()+"/n";
   tmp+=userPwd.getLabel()+userPwd.getString()+"/n";
   tmp+=email.getLabel()+email.getString()+"/n";
   tmp+=number.getLabel()+number.getString()+"/n";
   tmp+=value.getLabel()+value.getString()+"/n";
   tmp+=telnum.getLabel()+telnum.getString()+"/n";
   showMessage.setString(tmp);
   */
   
   //方法二：采用StringBuffer来实现，以提供资源利用率（建议使用此方法）。
   StringBuffer bf=new StringBuffer();
   bf.append(userName.getLabel());
   bf.append(userName.getString());
   bf.append("/n");
   bf.append(userPwd.getLabel());
   bf.append(userPwd.getString());
   bf.append("/n");
   bf.append(email.getLabel());
   bf.append(email.getString());
   bf.append("/n");
   bf.append(number.getLabel());
   bf.append(number.getString());
   bf.append("/n");
   bf.append(value.getLabel());
   bf.append(value.getString());
   bf.append("/n");
   bf.append(telnum.getLabel());
   bf.append(telnum.getString());
   bf.append("/n");
   showMessage.setString(new String(bf));
   
   display.setCurrent(showMessage); 
  }
  if(c==backCommand){
   //返回清空表单
   /*
   userName.setString("");
   userPwd.setString("");
   email.setString("");
   number.setString("");
   value.setString("");
   telnum.setString("");
   */
   display.setCurrent(myform);
  }
  if(c==exitCommand){
   destroyApp(false);
   notifyDestroyed();
  }
 }
}