1、编写程序,包括一个标签、一个文本框和一个按钮,但用户单击时,程序把文本框中的内容复制到标签中。
2、编写Applet程序实现一个计算器,包括10个数字(0-9)按钮和4个运算符(+ 、- 、* 、/ )按钮以及等号和清空两个辅助 按钮,还有一个显示输入的文本框。试分别用Borderlayout和GridLayout实现。
2、编写Applet程序实现一个计算器,包括10个数字(0-9)按钮和4个运算符(+ 、- 、* 、/ )按钮以及等号和清空两个辅助 按钮,还有一个显示输入的文本框。试分别用Borderlayout和GridLayout实现。
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.SpringLayout;
import javax.swing.UIManager;public class Copy extends JFrame
{
private SpringLayout layout = new SpringLayout();
private JLabel label = new JLabel(); private JTextField textField = new JTextField();
private JButton btnCopy = new JButton(); private static final long serialVersionUID = -8335262202165449039L; public static void main(String args[])
{
try
{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
new Copy().setVisible(true);
}
catch(Exception e)
{
e.printStackTrace();
}
} public Copy()
{
super();
getContentPane().setLayout(layout);
setSize(445, 175);
setTitle("Copy");
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
initUI();
}
private void initUI()
{
label.setBackground(Color.LIGHT_GRAY);
label.setOpaque(true);
btnCopy.setText("Copy");
getRootPane().setDefaultButton(btnCopy);
layout.putConstraint(SpringLayout.EAST, textField, -17, SpringLayout.EAST, getContentPane());
layout.putConstraint(SpringLayout.WEST, textField, 17, SpringLayout.WEST, getContentPane());
layout.putConstraint(SpringLayout.SOUTH, textField, 45, SpringLayout.NORTH, getContentPane());
layout.putConstraint(SpringLayout.NORTH, textField, 23, SpringLayout.NORTH, getContentPane());
layout.putConstraint(SpringLayout.EAST, label, -17, SpringLayout.EAST, getContentPane());
layout.putConstraint(SpringLayout.WEST, label, 17, SpringLayout.WEST, getContentPane());
layout.putConstraint(SpringLayout.SOUTH, label, 87, SpringLayout.NORTH, getContentPane());
layout.putConstraint(SpringLayout.NORTH, label, 65, SpringLayout.NORTH, getContentPane());
layout.putConstraint(SpringLayout.SOUTH, btnCopy, -7, SpringLayout.SOUTH, getContentPane());
layout.putConstraint(SpringLayout.NORTH, btnCopy, -30, SpringLayout.SOUTH, getContentPane());
layout.putConstraint(SpringLayout.EAST, btnCopy, -11, SpringLayout.EAST, getContentPane());
layout.putConstraint(SpringLayout.WEST, btnCopy, -97, SpringLayout.EAST, getContentPane());
getContentPane().add(textField);
getContentPane().add(label);
getContentPane().add(btnCopy);
btnCopy.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
label.setText(textField.getText());
}
});
}
}
if (temp == buttonMul) {
switch (prekey) {
case 0:
answerd += Double.parseDouble(textAnswer.getText());
break;
case 1:
answerd -= Double.parseDouble(textAnswer.getText());
break;
case 2:
answerd *= Double.parseDouble(textAnswer.getText());
break;
case 3:
if (Double.parseDouble(textAnswer.getText()) == 0) {
textAnswer.setText("除数不能为零");
clickable = false;
}
else
answerd /= Double.parseDouble(textAnswer.getText());
break;
default:
answerd = Double.parseDouble(textAnswer.getText());
}
textAnswer.setText("");
prekey = key = 2;
}
//'/'操作
if (temp == buttonDiv) {
switch (prekey) {
case 0:
answerd += Double.parseDouble(textAnswer.getText());
break;
case 1:
answerd -= Double.parseDouble(textAnswer.getText());
break;
case 2:
answerd *= Double.parseDouble(textAnswer.getText());
break;
case 3:
if (Double.parseDouble(textAnswer.getText()) == 0) {
textAnswer.setText("除数不能为零");
clickable = false;
}
else
answerd /= Double.parseDouble(textAnswer.getText());
break;
default:
answerd = Double.parseDouble(textAnswer.getText());
}
textAnswer.setText("");
prekey = key = 3;
}
}
//'='操作
if (temp == buttonEqual && clickable == true) {
//如果连续按'=',则进行连续运算
if (prekey == 5) {
if (key == 0) {
answerd += vard;
textAnswer.setText(df.format(answerd));
}
if (key == 1) {
answerd -= vard;
textAnswer.setText(df.format(answerd));
}
if (key == 2) {
answerd *= vard;
textAnswer.setText(df.format(answerd));
}
if (key == 3) {
if (Double.parseDouble(textAnswer.getText()) == 0) {
textAnswer.setText("除数不能为零");
clickable = false;
}
else {
answerd /= vard;
textAnswer.setText(df.format(answerd));
}
}
}
else {
vard = Double.parseDouble(textAnswer.getText());
if (key == 0) {
prekey = -1;
answerd += Double.parseDouble(textAnswer.getText());
textAnswer.setText(df.format(answerd));
}
if (key == 1) {
prekey = -1;
answerd -= Double.parseDouble(textAnswer.getText());
textAnswer.setText(df.format(answerd));
}
if (key == 2) {
prekey = -1;
answerd *= Double.parseDouble(textAnswer.getText());
textAnswer.setText(df.format(answerd));
}
if (key == 3) {
prekey = -1;
if (Double.parseDouble(textAnswer.getText()) == 0) {
textAnswer.setText("除数不能为零");
clickable = false;
}
else {
answerd /= Double.parseDouble(textAnswer.getText());
textAnswer.setText(df.format(answerd));
}
}
}
prekey = 5;
}
if (temp == buttonMod && clickable == true) {
if (answerd == 0) {
String s = textAnswer.getText();
textAnswer.setText(s);
}
else {
boolean isDot = false;
for (int i = 0; i < textAnswer.getText().length(); i++)
if ('.' == textAnswer.getText().charAt(i)) {
isDot = true;
break;
}
//如果是double数,除100
if (isDot == true) {
double dtemp = Double.parseDouble(textAnswer.getText());
dtemp = dtemp / 100.0;
textAnswer.setText(Double.toString(dtemp));
}
else {
//如果是int数但能被100整除,则去掉末尾两个零
if (Integer.parseInt(textAnswer.getText()) % 100 == 0) {
int itemp = Integer.parseInt(textAnswer.getText());
itemp /= 100;
textAnswer.setText(Integer.toString(itemp));
}
//如果是int数,但不能被100整除,则按double数处理
else {
double dtemp = Double.parseDouble(textAnswer.getText());
dtemp = dtemp / 100.0;
textAnswer.setText(Double.toString(dtemp));
}
}
}
}
//开根号运算
if (temp == buttonSqrt && clickable == true) {
String s = textAnswer.getText();
if (s.charAt(0) == '-') {
textAnswer.setText("负数不能开根号");
clickable = false;
}
else
textAnswer.setText(Double.toString(java.lang.Math.sqrt(Double.
parseDouble(textAnswer.getText()))));
}
//倒数运算
if (temp == buttonDao && clickable == true) {
if (textAnswer.getText().charAt(0) == '0' &&
textAnswer.getText().length() == 1) {
textAnswer.setText("零不能求倒数");
clickable = false;
}
else {
boolean isDec = true;
int i, j, k;
String s = Double.toString(1 / Double.parseDouble(textAnswer.getText()));
for (i = 0; i < s.length(); i++)
if (s.charAt(i) == '.')
break;
for (j = i + 1; j < s.length(); j++)
if (s.charAt(j) != '0') {
isDec = false;
break;
}
if (isDec == true) {
String stemp = "";
for (k = 0; k < i; k++)
stemp += s.charAt(k);
textAnswer.setText(stemp);
}
else
textAnswer.setText(s);
}
}
//按下'+/-'按钮时处理
if (temp == buttonAddAndSub && clickable == true) {
boolean isNumber = true;
String s = textAnswer.getText();
for (int i = 0; i < s.length(); i++)
if (! (s.charAt(i) >= '0' && s.charAt(i) <= '9' || s.charAt(i) == '.' ||
s.charAt(i) == '-')) {
isNumber = false;
break;
}
if (isNumber == true) {
//如果当前字符串首字母有'-'号,代表现在是个负数,再按下时,则将首符号去掉
if (s.charAt(0) == '-') {
textAnswer.setText("");
for (int i = 1; i < s.length(); i++) {
char a = s.charAt(i);
textAnswer.setText(textAnswer.getText() + a);
}
}
//如果当前字符串第一个字符不是符号,则添加一个符号在首字母处
else
textAnswer.setText('-' + s);
}
}
//计算器有关内存操作
//'MC'的操作,将内存清0
if (temp == buttonMC && clickable == true) {
memoryd = memoryi = 0;
textMemory.setText("");
}
//'MS'的操作,将当前文本框内容保存入内存,显示'M'
if (temp == buttonMS && clickable == true) {
boolean isDot = false;
textMemory.setText(" M");
for (int i = 0; i < textAnswer.getText().length(); i++)
if ('.' == textAnswer.getText().charAt(i)) {
isDot = true;
break;
}
//如果是double,则存入memoryd(double存储器)
if (isDot == true) {
memoryd = Double.parseDouble(textAnswer.getText());
memoryi = 0; //保证存储器中存放最新的值
}
//如果是int,则存入memoryi(int存储器)
else {
memoryi = Integer.parseInt(textAnswer.getText());
memoryd = 0; //保证存储器中存放最新的值
}
}
//'MR'的操作,将存储器中的信息输出
if (temp == buttonMR && clickable == true) {
if (memoryd != 0)
textAnswer.setText(Double.toString(memoryd));
if (memoryi != 0)
textAnswer.setText(Integer.toString(memoryi));
}
//'M+'的功能,将当前文本框里的数据和存储器中数据相加后,再存入存储器
if (temp == buttonMAdd && clickable == true) {
boolean isDot = false;
for (int i = 0; i < textAnswer.getText().length(); i++)
if ('.' == textAnswer.getText().charAt(i)) {
isDot = true;
break;
}
if (memoryi != 0) { //存储中是一个int型数
if (isDot == false) //被加数是一个int型数
memoryi += Integer.parseInt(textAnswer.getText());
else { //被加数是一个double型数,则将int存储器中数传入double存储器与当前数相加,int存储器清零
memoryd = memoryi + Double.parseDouble(textAnswer.getText());
memoryi = 0;
}
}
else
memoryd += Double.parseDouble(textAnswer.getText());
}
//按下'Backspace'键,利用循环将当前字符串中的最后一个字母删除
if (temp == buttonBk && clickable == true) {
String s = textAnswer.getText();
textAnswer.setText("");
for (int i = 0; i < s.length() - 1; i++) {
char a = s.charAt(i);
textAnswer.setText(textAnswer.getText() + a);
}
}
//按下'CE'按钮,将当前文本框内数据清除
if (temp == buttonCe) {
textAnswer.setText("");
clickable = true;
}
//按下'C'按钮,文本框内数据清除,同时var,answer清0
if (temp == buttonC) {
vard = answerd = 0;
textAnswer.setText("");
clickable = true;
}
//按下'复制'菜单栏
if (temp == copyItem) {
copy = textAnswer.getText();
}
//按下'粘贴'菜单栏
if (temp == pasteItem) {
textAnswer.setText(copy);
}
if (temp == sItem) {
JOptionPane.showMessageDialog(panel, "当前是标准型计算器,\n科学型计算器有待更新。");
}
//按下'帮助主题'菜单栏
if (temp == topHelp) {
JOptionPane.showMessageDialog(panel, scrollHelp);
}
//按下'数字分组'菜单栏
if (temp == numberGroup) {
if (numberGroup.getText().compareTo(" 数字分组(I)") == 0)
numberGroup.setText("√数字分组(I)");
else
numberGroup.setText(" 数字分组(I)");
}
//按下'关于'菜单栏
if (temp == aboutCal) {
JOptionPane.showMessageDialog(panel, "计算器1.00版\n开发者:05990113");
}
}
//输入中如果有操作非法,比如按下两次'+',捕获异常
catch (Exception e) {
textAnswer.setText("操作非法");
clickable = false;
}
}
//主函数
public static void main(String args[]) {
new Calculator();
}