QT实现计算器的基本功能

#include "widget.h" #include "ui_widget.h" Widget::Widget(QWidget *parent) : QWidget(parent) , ui(new Ui::Widget) { ui->setupUi(this); h.insert('+',1);//数字越大，优先级越高； h.insert('-',1); h.insert('*',2); h.insert('/',2); h.insert('%',2); QFont lineEdit_font("微软雅黑",20); ui->lineEdit->setFont(lineEdit_font); QPixmap delIcon("E:\\1111\\QtProgram\\Caclutor\\delbutton.png"); } Widget::~Widget() { delete ui; } //核心逻辑---计算,使用栈来完成: void Widget::on_equalButton_clicked() { //将QString转换为char* ； QByteArray str=program.toLatin1(); s=str.data(); int n=program.size(); //program是输入的字符串； for(int i=0;i<n;i++){ char c=s[i]; if(isdigit(c)) { int x=0,j=i; while(j<n&&isdigit(s[j])) { x=x*10+s[j++]-'0'; } i=j-1; no.push(x); } else if(c=='(') op.push(c); else if(c==')') { while(op.top()!='('){ eval(); } op.pop(); } else { while(op.size()&&op.top()!='('&&h[op.top()]>=h[c]){ eval(); } op.push(c); } }//for while(op.size()) eval(); res=no.top(); program=QString::number(res,10); ui->lineEdit->setText(program); } void Widget::eval() { int b=no.top(); no.pop(); int a=no.top(); no.pop(); char ch=op.top(); op.pop(); int x=0; if(ch=='+') x=a+b; else if(ch=='-') x=a-b; else if(ch=='*') x=a*b; else x=a/b; no.push(x); } void Widget::on_zeroButton_clicked() { program+="0"; ui->lineEdit->setText(program); } void Widget::on_oneButton_clicked() { program+="1"; ui->lineEdit->setText(program); } void Widget::on_twoButton_clicked() { program+="2"; ui->lineEdit->setText(program); } void Widget::on_threeButton_clicked() { program+="3"; ui->lineEdit->setText(program); } void Widget::on_fourButton_clicked() { program+="4"; ui->lineEdit->setText(program); } void Widget::on_fiveButton_clicked() { program+="5"; ui->lineEdit->setText(program); } void Widget::on_sixButton_clicked(){ program+="6"; ui->lineEdit->setText(program); } void Widget::on_sevenButton_clicked() { program+="7"; ui->lineEdit->setText(program); } void Widget::on_eightButton_clicked() { program+="8"; ui->lineEdit->setText(program); } void Widget::on_nineButton_clicked() { program+="9"; ui->lineEdit->setText(program); } void Widget::on_addButton_clicked() { program+="+"; ui->lineEdit->setText(program); } void Widget::on_subButton_clicked() { program+="-"; ui->lineEdit->setText(program); } void Widget::on_mulButton_clicked() { program+="*"; ui->lineEdit->setText(program); } void Widget::on_divButton_clicked() { program+="/"; ui->lineEdit->setText(program); } void Widget::on_remanButton_clicked() { program+="("; ui->lineEdit->setText(program); } void Widget::on_delButton_clicked() { program.chop(1);//将字符串末尾的一个字符删除 ui->lineEdit->setText(program); } void Widget::on_clearButton_clicked() { program.clear(); ui->lineEdit->clear(); } void Widget::on_pointButton_clicked() { program+=")"; ui->lineEdit->setText(program); }