Java计算器程序代码
用NetBeans创建窗体，再通过编写代码实现按钮的功能。步骤如下，因为是初学者，所以只实现了基本功能。
1)先创建计算机窗体
2）为各个按钮添加事件
private void jButton1MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
//调用setNum方法
setNum("1");
}
private void jButton2MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
setNum("2");
}
private void jButton3MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
setNum("3");
}
private void jButton4MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
setNum("4");
}
private void jButton5MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
setNum("5");
}
private void jButton6MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
setNum("6");
}
private void jButton7MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
setNum("7");
}
private void jButton8MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
setNum("8");
}
private void jButton9MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
setNum("9");
}
private void jButton18MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
//调用setYSF方法
setYSF("+");
}
private void jButton19MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
setYSF("*");
}
private void jButton12MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
setYSF("/");
}
private void jButton11MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
setYSF("-");
}
private void jButton15MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code her
setNum(".");
}
private void jButton13MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
setNum("0");
}
3）实现各个按钮的功能
//等于按钮的功能实现
private void dengyuMouseReleased(java.awt.event.MouseEvent evt) {
ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine se = manager.getEngineByName("js");
Double result = null;
try {
result = (Double) se.eval("(" + jTextField1.getText() + ")*1.0");
} catch (ScriptException ex) {
Logger.getLogger(JFrame.class.getName()).log(Level.SEVERE, null, ex);
jTextField1.setText("输入错误，按c重新输入");
}
jTextField1.setText(result.toString());
}
//退格按钮的功能实现
private void tuigeMouseReleased(java.awt.event.MouseEvent evt) {
//得到jTextField1中的文本
String strText = jTextField1.getText();
//判断文本的长度是否大于1
if(strText.length() > 1){
//如果大于1，删除最后一位
StringBuffer strBuf = new StringBuffer(strText);
strBuf.deleteCharAt(strBuf.length() - 1);
//把文本放回jTextField1
jTextField1.setText(strBuf.toString());
}else{
jTextField1.setText("0");
}
}
private void jButton16MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
jTextField1.setText("0");
}
//对数字进行处理
public void setNum(String str){
String strText = jTextField1.getText();、
//如果文本为0，那么显示按键的字符
if(strText.equals("0")){
jTextField1.setText(str);
}else{
//如果不是，就追加
StringBuffer strBuf = new StringBuffer(strText);
strBuf.append(str);
jTextField1.setText(strBuf.toString());
}
}
//对运算符进行处理
public void setYSF(String str){
String strText = jTextField1.getText();
//如果最后一位为运算符，那么换为按键字符
int lastRight = strText.length()-1;
char ch = strText.charAt(lastRight);
if(ch=='+'||ch=='-'||ch=='*'||ch=='/'){
String strResult = strText.substring(0, lastRight)+str;
jTextField1.setText(strResult);
//如果不是，那么可以继续加入按键字符
}else{
jTextField1.setText(strText+str);
}
}
4）运行文件
结果显示
