Qt学习笔记（二）---实现四则运算

用Qt实现一个可以实现四则运算的计算器：

#include "mainwindow.h" #include "ui_mainwindow.h" MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) { ui->setupUi(this); QObject::connect(ui->calButton,SIGNAL(clicked()),this,SLOT(calSlot())); } MainWindow::~MainWindow() { delete ui; } //goto click ---->on_calButton_clicked() void MainWindow::calSlot() { int first=ui->firstLineEdit->text().toInt(); int second=ui->secondLineEdit->text().toInt(); int result; if(ui->comboBox->currentIndex()==0) { result=first+second; //调用静态方法 QMessageBox::information(this,"Result",QString::number(result)); } if(ui->comboBox->currentIndex()==1) { result=first-second; //调用静态方法 QMessageBox::information(this,"Result",QString::number(result)); } if(ui->comboBox->currentIndex()==2) { result=first*second; //调用静态方法 QMessageBox::information(this,"Result",QString::number(result)); } if(ui->comboBox->currentIndex()==3) { if(second==0) { QMessageBox::warning(this,"Error Message","Second Can't be Zeros!!"); return; } result=first/second; //调用静态方法 QMessageBox::information(this,"Result",QString::number(result)); } //setText 设置文本 ui->resultLineEdit->setText(QString::number(result)); }