loginform.java

一个j2me很简单的用户名密码注册的登陆框源代码

import java.io.IOException;
import java.util.Enumeration;

import javax.microedition.lcdui.Alert;
import javax.microedition.lcdui.AlertType;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.TextField;

//登录界面
public class LoginForm extends Form implements CommandListener
{
	private Command back;
	private Command ok;
	
	private TextField userName;
	private TextField password;
	
	public LoginForm(String title)
	{
		super(title);
		
		back = new Command("返回", Command.BACK, 1);
		ok = new Command("确定", Command.OK, 1);
		
		userName = new TextField("用户名:", null, 20, TextField.ANY);
		password = new TextField("密码:", null, 20, TextField.PASSWORD);
		
		this.append(userName);
		this.append(password);
		this.addCommand(back);
		this.addCommand(ok);
		this.setCommandListener(this);
	}

	public void commandAction(Command c, Displayable d)
	{
		if (c.equals(back))
		{
			MyLoginMIDlet.midlet.showMainList();
		}
		else if (c.equals(ok))
		{	
			String un = userName.getString();
			String pwd = password.getString();
			
			Enumeration e = MyLoginMIDlet.userList.elements();
			while(e.hasMoreElements())
			{
				User user = (User)(e.nextElement());
				
				if (un.equals(user.getUserName()) && pwd.equals(user.getPWD()))
				{
					MyLoginMIDlet.midlet.showWelcomeList(user);
					return;
				}
			}
			
			password.setString(null);
			Alert al = new Alert("登录失败", "用户名或密码错误!", null, AlertType.ERROR);
			al.setTimeout(2000);
			MyLoginMIDlet.midlet.showAlert(al, this);
		}
	}

}