QT 简单的计算器例子

#include "hello.h"
#include <qthread.h>
#include <QVariant>
#include <qstring.h>

Hello::Hello(QWidget *parent)
: QDialog(parent)
{

ui.setupUi(this);
ui.leResult->setEnabled(false);
connect(ui.pbOK,SIGNAL(clicked()),this,SLOT(btnAdd()));
connect(ui.pbExit,SIGNAL(clicked()),this,SLOT(close()));
}

Hello::~Hello()
{

}

void Hello::btnOK()
{
ui.pbOK->setText("Cancel");
QThread::sleep(2);
connect(ui.pbOK,SIGNAL(clicked()),this,SLOT(close()));
}

void Hello::btnAdd()
{
QString num1 = ui.leNum1->text();
QString num2 = ui.leNum2->text();
double result;
switch(ui.cbOper->currentIndex())
{
case 0:
result = num1.toDouble() + num2.toDouble();
break;
case 1:
result =num1.toDouble() - num2.toDouble();
break;
case 2:
result = num1.toDouble() * num2.toDouble();
break;
case 3:
result = num1.toDouble() / num2.toDouble();
break;
}
ui.leResult->setText(QString::number(result));
}