java简单图形用户界面代码

//注册事件
loginBtn.addActionListener(this);
registerBtn.addActionListener(this);
cancalBtn.addActionListener(this);
this.setBounds(600,300,300,300);
this.pack();
re.pack();
re.setVisible(true);
}
if(e.getSource()==cancalBtn)
System.exit(0);
}
public static void main(String args[]){
Login login=new Login();
}
}
JOptionPane.showMessageDialog(null, "密码不能为空，请重新输入密码", "密码空提示", JOptionPane.OK_OPTION);
passwordPwd.requestFocus();
return;
}
else{
try{
String sendStr=name+"+"+pwd;
Socket socket=new Socket("127.0.0.1",8888);
DataInputStream dis=new DataInputStream(socket.getInputStream());
DataOutputStream dos=new DataOutputStream(socket.getOutputStream());
//定义组件
JPanel northPanel,southPanel,centerPanel,centerPanel1,centerPanel11,centerPanel12;
JButton loginBtn,registerBtn,cancalBtn;
JLabel userLbl,passwordLbl,titleLbl;
centerPanel11=new JPanel();
centerPanel12=new JPanel();
//标题
titleLbl=new JLabel("欢迎进入考试系统");
titleLbl.setFont(new Font("隶书",Font.BOLD,24));
northPanel.add(titleLbl);
Toolkit tool = Toolkit.getDefaultToolkit();
Dimension ds = tool.getScreenSize();
int w = ds.width;
int h = ds.height;
re.setBounds((w-300)/2,(h-300)/2, 300, 300);
this.setResizable(false);
this.setVisible(true);
}
public void actionPerformed(ActionEvent e){
if(tSource()==loginBtn){
name=userTxt.getText().trim();
String pwd=new String(passwordPwd.getPassword());
if (name.equals("")){
JOptionPane.showMessageDialog(null, "用户名不能为空，请重新输入用户名", "用户名空提示", JOptionPane.OK_OPTION);
userTxt.requestFocus();
return;
}
else if (pwd.equals("")){
this.add(northPanel,BorderLayout.NORTH);
//中间部分
centerPanel1.setLayout(new BorderLayout());
userLbl=new JLabel("用户名");
userTxt=new JTextField(12);
centerPanel11.add(userLbl);
package dsr;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import .Socket;
public class Login extends JFrame implements ActionListener{
centerPanel11.add(userTxt);
centerPanel1.add(centerPanel11,BorderLayout.NORTH);
passwordLbl=new JLabel("密码");
passwordPwd=new JPasswordField(12);
centerPanel12.add(passwordLbl);
registerBtn=new JButton("注册");
cancalBtn=new JButton("取消");
southPanel.add(loginBtn);
southPanel.add(registerBtn);
southPanel.add(cancalBtn);
this.add(southPanel,BorderLayout.SOUTH);
}
}catch(FileNotFoundException e1){
e1.getStackTrace();
}catch(IOException e2){
e2.getStackTrace();
}
}
}
if(e.getSource()==registerBtn){
JFrame re=new Register();
JTextField userTxt;
JPasswordField passwordPwd;
static String name;
public Login ()
{
super("用户登录");
northPanel=new JPanel();
southPanel=new JPanel();
centerPanel1=new JPanel();
dos.writeUTF(sendStr);
String recieveStr=dis.readUTF();
if (recieveStr.equals("ok")){
JOptionPane.showMessageDialog(null, "进入考试", "试卷", RMATION_MESSAGE);
centerPanel12.add(passwordPwd);
centerPanel1.add(centerPanel12,BorderLayout.CENTER);
this.add(centerPanel1,BorderLayout.CENTER);
//按钮部分
loginBtn=new JButton("登录");