java语言综合设计实验报告(5)

// ′=′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;

resultIndicate = true; }

// 显示PI

if (temp == buttonPI && clickable == true) {

textAnswer.setText(Double.toString(java.lang.Math.PI)); }

// 求正弦运算

if (temp == buttonSin && clickable == true) {

textAnswer.setText(Double.toString(java.lang.Math.sin(Double. parseDouble(textAnswer.getText()) * java.lang.Math.PI / 180))); }

// 求余弦运算

if (temp == buttonCos && clickable == true) {

textAnswer.setText(Double.toString(java.lang.Math.cos(Double. parseDouble(textAnswer.getText()) * java.lang.Math.PI / 180))); }

// 求正切运算

if (temp == buttonTan && clickable == true) {

textAnswer.setText(Double.toString(java.lang.Math.tan(Double.

parseDouble(textAnswer.getText()) * java.lang.Math.PI / 180))); }

// 求平方运算

if (temp == buttonX2 && clickable == true) {

answerd = Double.parseDouble(textAnswer.getText()) * Double.parseDouble(textAnswer.getText()); textAnswer.setText(Double.toString(answerd)); }

// 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())))); }

// 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) { 则将首符号去掉 a);

处

// 如果当前字符串首字母有′-′号,代表现在是个负数,再按下时,if (s.charAt(0) == '-') { textAnswer.setText(\);

for (int i = 1; i < s.length(); i++) { char a = s.charAt(i);

textAnswer.setText(textAnswer.getText() + } }

// 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

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(\);

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if (temp == buttonMAdd && clickable == true) { boolean isDot = false;

for (int i = 0; i < textAnswer.getText().length(); i++) if ('.' == textAnswer.getText().charAt(i)) {

储器

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 == buttonBS && 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清零 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); } }

// 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;

六、设计体会

通过这门课程的学习，我了解到了java语言的强大功能，虽然我不是计算机专业的学生，但是我对编程很感兴趣，大一学习c语言的时候，我从头到尾都很认真，经常自己编一些很有意思的小程序，对于java语言，只是听说过而已。

通过这次设计，我发现了java语言独特的魅力，第一，代码可用性高，类可以随意调用，这使的编程序省了不少力，第二，代码的可读性好，只要会英语，代码基本能看懂。第三，不限硬件，几乎兼容所有的计算机，因为它在java虚拟机上运行。总的来说java是一种趋势，它掀起了一场跨平台的编程革命，还是很不错的。