登錄窗口一般很常見，現在讓我們自己也來寫一個吧！
PS：很多import是重複的，是因為我是分了幾個類寫的，必須單獨導入
//模擬qq登錄窗口import java.awt.*;import java.io.*;import java.awt.event.*;import javax.swing.*;public class QQGUI extends JFrame implements ActionListener{ private JLabel userLa; private JLabel pwdLa; private JLabel verCodeLa;//驗證碼private JTextField userTxt; private JPasswordField pwdTxt; private JTextField verCodeTxt;//驗證碼private JButton sureBt; private JButton quitBt; private Mypanel mp; //構造方法public QQGUI() { Init(); } public void Init() { Frame frame = new Frame("QQ登錄"); //創建出控件對象（因為上面只是聲明出來，並沒有給出實際的空間) //用戶文本userLa = new JLabel(); userLa.setText("用戶名："); userLa.setSize(60, 50); userLa.setLocation(100, 80); //密碼文本pwdLa = new JLabel(); pwdLa.setText("密碼："); pwdLa.setSize(50, 50); pwdLa.setLocation(100, 120); //用戶輸入框userTxt = new JTextField(); userTxt.setSize(100, 20); //this.setSize(width, height) userTxt.setLocation(170, 95); //密碼輸入框pwdTxt = new JPasswordField(); pwdTxt.setSize(100, 20); pwdTxt.setLocation(170, 135); //確認按鈕sureBt = new JButton("登錄"); sureBt.setSize(60, 25); sureBt.setLocation(135, 260); //退出按鈕quitBt = new JButton("退出"); quitBt.setSize(60, 25); quitBt.setLocation(240, 260); //驗證碼文本verCodeLa = new JLabel(); verCodeLa.setText("驗證碼："); verCodeLa.setSize(60, 50); verCodeLa.setLocation(100,165); //驗證碼文本框verCodeTxt = new JTextField(); verCodeTxt.setSize(100, 20); verCodeTxt.setLocation(170, 180); //驗證碼mp = new Mypanel(); mp.setSize(100, 30); mp.setLocation(280, 175); //登錄方式選擇框JComboBox xlk=new JComboBox(); xlk.setSize(60, 20); xlk.setLocation(250, 220); xlk.addItem("在線"); xlk.addItem("隱身"); xlk.addItem("離開"); this.setLayout(null); this.setSize(500, 400); this.add(userLa); this.add(pwdLa); this.add(userTxt); this.add(pwdTxt); this.add(sureBt); this.add(quitBt); this.add(verCodeLa); this.add(verCodeTxt); this.add(mp); this.add(xlk); sureBt.addActionListener(this); quitBt.addActionListener(this); this.setVisible(true); } //具體事件的處理public void actionPerformed(ActionEvent e) { //獲取產生事件的事件源強制轉換JButton bt = (JButton)e.getSource(); //獲取按鈕上顯示的文本String str = bt.getText(); if(str.equals("登錄")) { if(!CheckIsNull()) { //獲取用戶所輸入的用戶名String user = userTxt.getText().trim(); //獲取用戶所輸入的密碼String pwd = pwdTxt.getText().trim(); if(checkUserAndPwd(user,pwd)) { //隱藏當前登錄窗口this.setVisible(false); //驗證成功創建一個主窗口MainFrame frame = new MainFrame(); } else { //如果錯誤則彈出一個顯示框JOptionPane pane = new JOptionPane("用戶或密碼錯誤"); JDialog dialog = pane.createDialog(this,"警告"); dialog.show(); } } } else { //調用系統類中的一個正常退出System.exit(0); } } private boolean CheckIsNull() { boolean flag = false; if(userTxt.getText().trim().equals(" ")) { flag = true; } else { if(pwdTxt.getText().trim().equals(" ")) { flag = true; } } return flag; } private boolean checkUserAndPwd(String user,String pwd) { boolean result = false; try { FileReader file = new FileReader("D://Workspaces//MyEclipse 8.5//testGUI.txt"); BufferedReader bre = new BufferedReader(file); String str = bre.readLine(); while(str!=null) { String[] strs = str.split(","); if(strs[0].equals(user)) { if(strs[1].equals(pwd)) result = true; } str = bre.readLine(); } file.close(); }catch(Exception ex) { System.out.print(""); } return result; }}//MainFrame類import javax.swing.*;public class MainFrame extends JFrame { public MainFrame() { this.setSize(300, 300); this.setVisible(true); }}//驗證碼的生成import java.awt.*;import java.util.*;public class Mypanel extends Panel { public void paint(Graphics g) { int height = 50; int width = 90; //驗證碼框背景顏色g.setColor(Color.LIGHT_GRAY); //填充驗證碼背景g.fillRect(0, 0, width, height); g.setColor(Color.BLACK); g.drawRect(0, 0, width-1, height-1); Random r = new Random(); //設置干擾點for(int i = 0;i<100;i++) { int x = r.nextInt(width)-1; int y = r.nextInt(height)-1; g.drawOval(x, y, 2, 2); } g.setFont(new Font("黑體",Font.BOLD,20));//設置驗證碼字體以及大小g.setColor(Color.RED);//設置驗證碼字體顏色//生成隨機驗證碼char[] tmp = ("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ").toCharArray(); StringBuilder sb = new StringBuilder(); for(int i = 0;i<4;i++) { int pos = r.nextInt(tmp.length); char c = tmp[pos]; sb.append(c + " "); } g.drawString(sb.toString(), 10, 15);//寫入驗證碼}}//下拉框的實現import java.awt.*;import java.awt.event.*;import javax.swing.*;public class xialakuang extends JFrame { private JComboBox comboBox;//定義一個組合框public void xia () { //JPanel panel = new JPanel();//創建一個JPanel面板comboBox = new JComboBox(); comboBox.addItem("在線"); comboBox.addItem("隱身"); comboBox.addItem("離開"); this.add(comboBox); //this.add(panel); this.setSize(200, 100); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); this.setVisible(true); }}//測試public class testQQGUI { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub QQGUI frame = new QQGUI(); }}以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持武林網。