这个计算器的界面模仿windows自带的简易计算器，包括交互界面和和对各种输入的响应。目前尚未实现菜单栏和记忆类按钮的功能
import java.awt.color;
import java.awt.container;
import java.awt.gridlayout;
import java.awt.insets;
import java.awt.event.actionevent;
import java.awt.event.actionlistener;
import javax.swing.jframe;
import javax.swing.jbutton;
import javax.swing.jmenu;
import javax.swing.jmenubar;
import javax.swing.jmenuitem;
import javax.swing.jpanel;
import javax.swing.jtextfield;
import javax.swing.swingconstants;
import javax.swing.plaf.basic.basicborders;
public class calculator extends jframe {
private static final long serialversionuid = 1l;
container c = getcontentpane();
stringbuilder number1 = new stringbuilder("");// 储存第1个数字字符串
stringbuilder number2 = new stringbuilder("");// 储存第2个数字字符串
stringbuilder operator = new stringbuilder("");// 储存运算符
stringbuilder result = new stringbuilder("");// 储存运算结果
jtextfield numbershow = new jtextfield("0.");// 数字显示区域，初始显示为"0."
public static void main(string[] args) {// 主方法
calculator c1 = new calculator();
c1.setvisible(true);
}
public calculator() {// 计算器构造方法
settitle("计算器");
setbounds(100, 100, 260, 245);
setresizable(false);
setlayout(null);
setdefaultcloseoperation(jframe.exit_on_close);
createmenubar();// 创建菜单栏
createnumbershow();// 创建数字显示区域
creatememoshow();// 创建记忆显示
createclearbuttons();// 创建backspace,ce,c等三个按钮
createbuttonarea();// 创建数字按钮区域
}
private void createmenubar() {// 创建菜单栏的方法
jmenubar menubar = new jmenubar();
setjmenubar(menubar);
jmenu menu1 = new jmenu("编辑");
jmenu menu2 = new jmenu("查看");
jmenu menu3 = new jmenu("帮助");
menubar.add(menu1);
menubar.add(menu2);
menubar.add(menu3);
jmenuitem menu1item1 = new jmenuitem("复制");
jmenuitem menu1item2 = new jmenuitem("粘贴");
jmenuitem menu2item1 = new jmenuitem("标准型");
jmenuitem menu2item2 = new jmenuitem("科学型");
jmenuitem menu2item3 = new jmenuitem("科学分组");
jmenuitem menu3item1 = new jmenuitem("帮助主题");
jmenuitem menu3item2 = new jmenuitem("关于计算器");
menu1.add(menu1item1);
menu1.add(menu1item2);
menu2.add(menu2item1);
menu2.add(menu2item2);
menu2.add(menu2item3);
menu3.add(menu3item1);
menu3.add(menu3item2);
}
private void createnumbershow() {// 创建数字显示区域的方法
numbershow.sethorizontalalignment(jtextfield.right);
numbershow.setbounds(5, 0, 245, 22);
numbershow.setenabled(false);
numbershow.setdisabledtextcolor(color.black);
c.add(numbershow);
}
private void creatememoshow() {// 创建记忆显示的方法
jtextfield memoshow = new jtextfield();
memoshow.seteditable(false);
memoshow.setbounds(10, 30, 28, 22);
memoshow.setborder(new basicborders.fieldborder(color.black,
color.black, color.white, color.white));
c.add(memoshow);
}
private void createclearbuttons() {// 创建backspace,ce,c等三个按钮的方法
jbutton[] clearbutton = new jbutton[3];
string[] clearbuttontext = { "backspace", "ce", "c" };
for (int i = 0; i < 3; i++) {
clearbutton[i] = new jbutton();
clearbutton[i].settext(clearbuttontext[i]);
clearbutton[i].sethorizontalalignment(swingconstants.center);
clearbutton[i].setmargin(new insets(0, 0, 0, 0));
clearbutton[i].setfont(new java.awt.font("arial", 0, 9));
clearbutton[i].setforeground(color.blue);
clearbutton[i].setbounds(48 + i * 68, 30, 63, 22);
clearbutton[i].setforeground(color.red);
c.add(clearbutton[i]);
}
clearbutton[0].addactionlistener(new actionlistener() {// 为backspace按钮添加监听器
@override
public void actionperformed(actionevent e) {
if (number1.tostring().equals("")) {// 如果未做任何输入
shownumber(numbershow, number1);// 显示number1
} else if (operator.tostring().equals("")) {// 如果只输入了number1
number1.deletecharat(number1.tostring().length() - 1);// 将number1的最后一个字符去掉
shownumber(numbershow, number1);// 显示number1
} else if (number2.tostring().equals("")) {// 如果只输入了number1和operator
shownumber(numbershow, number1);// 不作任何处理，显示number1
} else {// 如果输入了number1、operator、number2
number2.deletecharat(number2.tostring().length() - 1);// 将number2的最后一个字符去掉
shownumber(numbershow, number2);// 显示number2
}
}
});
clearbutton[1].addactionlistener(new actionlistener() {// 为ce按钮添加监听器
@override
public void actionperformed(actionevent e) {
if (number1.tostring().equals("")) {// 如果未做任何输入
shownumber(numbershow, number1);// 显示number1
} else if (operator.tostring().equals("")) {// 如果只输入了number1
number1.setlength(0);// 清除number1
shownumber(numbershow, number1);// 显示number1
} else if (number2.tostring().equals("")) {// 如果输入了number1和operator
shownumber(numbershow, number2);// 不作任何处理，显示number2
} else {// 如果输入了number1、operator、number2
number2.setlength(0);// 清除number2
shownumber(numbershow, number2);// 显示number2
}
}
});
clearbutton[2].addactionlistener(new actionlistener() {// 为c按钮添加监听器
@override
public void actionperformed(actionevent e) {// 将所有储存清零
number1.setlength(0);
number2.setlength(0);
operator.setlength(0);
numbershow.settext("0.");
result.setlength(0);
}
});
}
private void createbuttonarea() {// 创建数字按钮区域的方法
jpanel buttonarea = new jpanel();
buttonarea.setbounds(5, 55, 245, 125);
buttonarea.setlayout(new gridlayout(4, 6, 5, 5));
c.add(buttonarea);
jbutton[] numberbutton = new jbutton[24];
string[] numberbuttontext = { "mc", "7", "8", "9", "/", "sqrt", "mr",
"4", "5", "6", "*", "%", "ms", "1", "2", "3", "-", "1/x", "m+",
"0", "+/-", ".", "+", "=" };
for (int i = 0; i < 24; i++) {// 使用循环为这24个按钮添加标识
numberbutton[i] = new jbutton(numberbuttontext[i]);
buttonarea.add(numberbutton[i]);
if (i % 6 == 0 || i % 6 == 4 || i == 23) {// 操作符按钮设置为红色
numberbutton[i].sethorizontalalignment(swingconstants.center);
numberbutton[i].setmargin(new insets(0, 0, 0, 0));
numberbutton[i].setfont(new java.awt.font("arial", 0, 9));
numberbutton[i].setforeground(color.red);
} else {// 其它设置为蓝色
numberbutton[i].sethorizontalalignment(swingconstants.center);
numberbutton[i].setmargin(new insets(0, 0, 0, 0));
numberbutton[i].setfont(new java.awt.font("arial", 0, 9));
numberbutton[i].setforeground(color.blue);
}
}
int[] numbers = { 19, 13, 14, 15, 7, 8, 9, 1, 2, 3 };// 该数组中的数字分别代表0-9等数字在numberbuttontext数组中序号
for (int i = 0; i <= 9; i++) { // 使用循环为这0-9这十个数字按钮添加监听器
final string str = string.valueof(i);
numberbutton[numbers[i]].addactionlistener(new actionlistener() {// 为0-9按钮添加监听器
@override
public void actionperformed(actionevent e) {
if (operator.tostring().equals("")) {// 没有输入operator之前
add(number1, str); // 只设置number1的值
shownumber(numbershow, number1);// 只显示number1的值
} else {// 输入operator之后
add(number2, str);// 只设置number2的值
shownumber(numbershow, number2);// 只显示number2的值
}
}
});
}
numberbutton[20].addactionlistener(new actionlistener() { // 为"+/-"按钮添加监听器
@override
public void actionperformed(actionevent e) {
if (operator.tostring().equals("")) {// 没有输入operator之前
add(number1, "+/-");// 只设置number1的值
shownumber(numbershow, number1);// 只显示number1的值
} else {// 输入operator之后
add(number2, "+/-");// 只设置number2的值
shownumber(numbershow, number2);// 只显示number2的值
}
}
});
numberbutton[21].addactionlistener(new actionlistener() { // 为"."按钮添加监听器
@override
public void actionperformed(actionevent e) {
if (operator.tostring().equals("")) {// 在输入operator之前，只显示number1的值
add(number1, ".");
shownumber(numbershow, number1);
} else {// 在输入operator之后，只显示number2的值
add(number2, ".");
shownumber(numbershow, number2);
}
}
});
numberbutton[22].addactionlistener(new actionlistener() { // 为"+"按钮添加监听器
@override
public void actionperformed(actionevent e) {
operator.setlength(0);
operator.append("+");
}
});
numberbutton[16].addactionlistener(new actionlistener() { // 为"-"按钮添加监听器
@override
public void actionperformed(actionevent e) {
operator.setlength(0);
operator.append("-");
}
});
numberbutton[10].addactionlistener(new actionlistener() { // 为"*"按钮添加监听器
@override
public void actionperformed(actionevent e) {
operator.setlength(0);
operator.append("*");
}
});
numberbutton[4].addactionlistener(new actionlistener() { // 为"/"按钮添加监听器
@override
public void actionperformed(actionevent e) {
operator.setlength(0);
operator.append("/");
}
});
numberbutton[23].addactionlistener(new actionlistener() { // 为"="按钮添加监听器
@override
public void actionperformed(actionevent e) {
if (number1.tostring().equals("")) {// 当number1为空时
shownumber(numbershow, number1);
} else if (operator.tostring().equals("")) {// 当number1不为空，而operator为空时
shownumber(numbershow, number1);
} else if (number2.tostring().equals("")) {// 当number1、operator均不为空，而number2为空时
switch (operator.tostring()) {
case ("+"): {
number2.append(number1.tostring());
double d = double.parsedouble(number1
.tostring())
+ double.parsedouble(number2.tostring());
result.setlength(0);
result.append(d);
shownumber(numbershow, result);
number1.setlength(0);
number1.append(d);
}
break;
case ("-"): {
number2.append(number1.tostring());
double d = double.parsedouble(number1
.tostring())
- double.parsedouble(number2.tostring());
result.setlength(0);
result.append(d);
shownumber(numbershow, result);
number1.setlength(0);
number1.append(d);
}
break;
case ("*"): {
number2.append(number1.tostring());
double d = double.parsedouble(number1
.tostring())
* double.parsedouble(number2.tostring());
result.setlength(0);
result.append(d);
shownumber(numbershow, result);
number1.setlength(0);
number1.append(d);
}
break;
case ("/"): {
number2.append(number1.tostring());
double d = double.parsedouble(number1
.tostring())
/ double.parsedouble(number2.tostring());
result.setlength(0);
result.append(d);
shownumber(numbershow, result);
number1.setlength(0);
number1.append(d);
}
break;
}
} else {// 当number1、operator、number2均不为空时
switch (operator.tostring()) {
case ("+"): {
double d = double.parsedouble(number1
.tostring())
+ double.parsedouble(number2.tostring());
result.setlength(0);
result.append(d);
shownumber(numbershow, result);
number1.setlength(0);
number1.append(d);
}
break;
case ("-"): {
double d = double.parsedouble(number1
.tostring())
- double.parsedouble(number2.tostring());
result.setlength(0);
result.append(d);
shownumber(numbershow, result);
number1.setlength(0);
number1.append(d);
}
break;
case ("*"): {
double d = double.parsedouble(number1
.tostring())
* double.parsedouble(number2.tostring());
result.setlength(0);
result.append(d);
shownumber(numbershow, result);
number1.setlength(0);
number1.append(d);
}
break;
case ("/"): {
double d = double.parsedouble(number1
.tostring())
/ double.parsedouble(number2.tostring());
result.setlength(0);
result.append(d);
shownumber(numbershow, result);
number1.setlength(0);
number1.append(d);
}
break;
}
}
}
});
numberbutton[17].addactionlistener(new actionlistener() { // 为"1/x"按钮添加监听器
@override
public void actionperformed(actionevent e) {
if (number1.tostring().equals("")) {// 没有输入number1时
numbershow.settext("除数不能为零");
} else if (operator.tostring().equals("")) {// 输入了number1，但没有输入operator
if (double.parsedouble(number1.tostring()) == 0) {// 如果number1的值为零
numbershow.settext("除数不能为零");
} else {// 如果number1的值不为零
double d = 1 / (double.parsedouble(number1
.tostring()));
number1.setlength(0);
number1.append(d);// 将number1的值开放并存储
shownumber(numbershow, number1);
}
} else if (number2.tostring().equals("")) {// 输入了number1、operator，但没有输入number2
double d = 1 / (double.parsedouble(number1
.tostring()));
number2.append(d);// 将number1的值开放并存储
shownumber(numbershow, number2);
} else {// 输入了number1、operator，number2
double d = 1 / (double.parsedouble(number2
.tostring()));
number2.setlength(0);
number2.append(d);// 将number2的值开放并存储
shownumber(numbershow, number2);
}
}
});
numberbutton[11].addactionlistener(new actionlistener() { // 为"%"按钮添加监听器
@override
public void actionperformed(actionevent e) {
// 暂时空缺
}
});
numberbutton[5].addactionlistener(new actionlistener() { // 为"sqrt"按钮添加监听器
@override
public void actionperformed(actionevent e) {
if (number1.tostring().equals("")) {// 没有输入number1时
shownumber(numbershow, number1);
} else if (operator.tostring().equals("")) {// 输入了number1，但没有输入operator
if (double.parsedouble(number1.tostring()) < 0) {// number1小于0
numbershow.settext("函数输入无效");
} else {// number1大于0
double d = math.sqrt(double.parsedouble(number1
.tostring()));
number1.setlength(0);
number1.append(d);// 将number1的值开放并存储
shownumber(numbershow, number1);
}
} else if (number2.tostring().equals("")) {// 输入了number1、operator，但没有输入number2
double d = math.sqrt(double.parsedouble(number1
.tostring()));
number2.append(d);// 将number1的值开放并存储
shownumber(numbershow, number2);
} else {// 输入了number1、operator、number2
double d = math.sqrt(double.parsedouble(number2
.tostring()));
number2.setlength(0);
number2.append(d);// 将number2的值开放并存储
shownumber(numbershow, number2);
}
}
});
}
public void add(stringbuilder s1, string s2) {// 定义按钮输入后数字字符串变化的方法
if (s2.equals("+/-")) {// 定义输入"+/-"后数字字符串的变化
if (s1.tostring().equals("") || s1.tostring().equals("0")) {// 如果数字字符串为空或者0，那么不发生变化
s1.append("");
} else {// 如果数字字符串不为空也不为0，那么在数字字符串前增加或删除"-"字符
if (s1.tostring().startswith("-")) {
s1.deletecharat(0);
} else {
s1.insert(0, "-");
}
}
}
if (s2.equals(".")) {// 定义输入"."后数字字符串的变化
if (s1.tostring().indexof(".") == -1) {// 查找数字字符串中是否含有"."字符，如果没有则执行以下代码
if (s1.tostring().equals("")) {// 如果数字字符串为空，那么将数字字符串设置为"0."
s1.setlength(0);
s1.append("0.");
} else {
s1.append(".");
}
} else {// 如果有，则不发生变化
s1.append("");
}
}
if (s2.equals("0")) {// 定义输入"0"后数字字符串的变化
if (s1.tostring().equals("0")) {// 当数字的字符串为"0"时，不发生变化
s1.append("");
} else {// 当数字的字符串吧为"0"时，在其字符串后增加"0"
s1.append("0");
}
}
for (int i = 1; i < 10; i++) {// 通过循环，定义输入1-9后数字字符串的变化
string str = string.valueof(i);
if (s2.equals(str)) {// 定义输入1-9后数字字符串的变化
if (s1.tostring().equals("0")) {
s1.setlength(0);
s1.append(str);
} else
s1.append(str);
}
}
}
public void shownumber(jtextfield j, stringbuilder s) {// 定义数字显示区域如何显示数字字符串的方法
if (s.tostring().equals("") == true || s.tostring().equals("0") == true) {
j.settext("0.");
} else if (s.tostring().indexof(".") == -1) {
j.settext(s.tostring() + ".");
} else {
j.settext(s.tostring());
}
}
}
更多java模仿windows计算器示例。