JavaJFrame实现的简易计算器

package item; import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.*; public class Calculator { static JTextField textField; static int num1 = 0; static int num2 = 0; public static void main(String[] args) { // 网格布局 Font font = new Font("黑体", Font.BOLD, 32); UIManager.put("Button.font", font); JFrame frame = new JFrame("计算器"); textField = new JTextField(24);// 文本最大输入长度。 textField.setPreferredSize(new Dimension(12, 66));// --可以使用Dimension方法来设置布局内部组件地大小。 textField.setFont(new Font("宋体", Font.PLAIN, 24)); JButton button = new JButton("1"); JButton button1 = new JButton("2"); JButton button2 = new JButton("3"); JButton button3 = new JButton("+"); JButton button4 = new JButton("4"); JButton button5 = new JButton("5"); JButton button6 = new JButton("6"); JButton button7 = new JButton("-"); JButton button8 = new JButton("7"); JButton button9 = new JButton("8"); JButton button10 = new JButton("9"); JButton button11 = new JButton("x"); JButton button12 = new JButton("c"); JButton button13 = new JButton("0"); JButton button14 = new JButton("/"); JButton button15 = new JButton("="); JPanel panel = new JPanel(); panel.setLayout(new GridLayout(4, 4, 4, 4)); // -----------------------事件------------------------- ActionListener actionListener = new ActionListener() { @Override public void actionPerformed(ActionEvent e) { // TODO Auto-generated method stub String content = e.getActionCommand(); String message = textField.getText(); switch (content) { case "1": message = message + 1; textField.setText(message); break; case "2": message = message + 2; textField.setText(message); break; case "3": message = message + 3; textField.setText(message); break; case "4": message = message + 4; textField.setText(message); break; case "5": message = message + 5; textField.setText(message); break; case "6": message = message + 6; textField.setText(message); break; case "7": message = message + 7; textField.setText(message); break; case "8": message = message + 8; textField.setText(message); break; case "9": message = message + 9; textField.setText(message); break; case "0": message = message + 0; textField.setText(message); break; case "c": message = ""; textField.setText(message); break; case "+": message = message + "+"; textField.setText(message); break; case "-": message = message + "-"; textField.setText(message); break; case "x": message = message + "x"; textField.setText(message); break; case "/": message = message + "/"; textField.setText(message); break; case "=": int a = message.indexOf("+"); int b = message.indexOf("-"); int c = message.indexOf("x"); int d = message.indexOf("/"); if (b == -1) { if (a != -1) { String[] strings = message.split("\\+", 2); String s1 = strings[0]; String s2 = strings[1]; num1 = Integer.parseInt(s1); num2 = Integer.parseInt(s2); message = (num1 + num2) + ""; textField.setText(message); } if (c != -1) { String[] strings = message.split("x", 2); String s1 = strings[0]; String s2 = strings[1]; num1 = Integer.parseInt(s1); num2 = Integer.parseInt(s2); message = (num1 * num2) + ""; textField.setText(message); } if (d != -1) { String[] strings = message.split("\\/", 2); String s1 = strings[0]; String s2 = strings[1]; num1 = Integer.parseInt(s1); num2 = Integer.parseInt(s2); message = (1.0 * num1 / num2) + ""; textField.setText(message); } } if (b != -1) { if (a != -1) { String[] strings = message.split("\\+", 2); String s1 = strings[0]; String s2 = strings[1]; num1 = Integer.parseInt(s1); num2 = Integer.parseInt(s2); message = (num1 + num2) + ""; textField.setText(message); } if (c != -1) { String[] strings = message.split("x", 2); String s1 = strings[0]; String s2 = strings[1]; num1 = Integer.parseInt(s1); num2 = Integer.parseInt(s2); message = (num1 * num2) + ""; textField.setText(message); } if (d != -1) { String[] strings = message.split("\\/", 2); String s1 = strings[0]; String s2 = strings[1]; num1 = Integer.parseInt(s1); num2 = Integer.parseInt(s2); message = (1.0 * num1 / num2) + ""; textField.setText(message); } if (b == 0 && a == -1 && c == -1 && d == -1) { String[] strings = message.split("\\-", 3); String s1 = strings[1]; String s2 = strings[2]; num1 = Integer.parseInt(s1); num2 = Integer.parseInt(s2); message = (-(num1 + num2)) + ""; textField.setText(message); } if (b > 0 && a == -1 && c == -1 && d == -1) { String[] strings = message.split("\\-", 2); String s1 = strings[0]; String s2 = strings[1]; num1 = Integer.parseInt(s1); num2 = Integer.parseInt(s2); message = (num1 - num2) + ""; textField.setText(message); } } break; default: } } }; // ---------- button.addActionListener(actionListener); button1.addActionListener(actionListener); button2.addActionListener(actionListener); button3.addActionListener(actionListener); button4.addActionListener(actionListener); button5.addActionListener(actionListener); button6.addActionListener(actionListener); button7.addActionListener(actionListener); button8.addActionListener(actionListener); button9.addActionListener(actionListener); button10.addActionListener(actionListener); button11.addActionListener(actionListener); button12.addActionListener(actionListener); button13.addActionListener(actionListener); button14.addActionListener(actionListener); button15.addActionListener(actionListener); // -------------------------------------------------- // frame.add(button); panel.add(button); panel.add(button1); panel.add(button2); panel.add(button3); panel.add(button4); panel.add(button5); panel.add(button6); panel.add(button7); panel.add(button8); panel.add(button9); panel.add(button10); panel.add(button11); panel.add(button12); panel.add(button13); panel.add(button14); panel.add(button15); frame.add(textField, BorderLayout.NORTH); frame.add(panel, BorderLayout.CENTER); // frame.pack(); frame.setBounds(400, 400, 280, 340); frame.setResizable(false);// 大小不可变 frame.setLocationRelativeTo(null);// 设置frame总位于屏幕中心。 frame.setVisible(true); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);// 退出将关闭程序。 } }