qt编程简单的计算器.doc

QT编程实现简易的计算器
一、 实验目的
1) 熟悉QtCreator的简单操作。 2) 了解Qt程序编写框架。 
3) 了解信号和槽机制，熟练掌握信号与槽在应用程序中的使用。 
二、 实验内容 
1) 查看API手册，学习简单的Qt类的使用，如QLineEdit、QPushButton
等。 
2) 用QtCreator创建工程，用Qt编写计算器程序。 3) 对计算器程序进行移植。 
三、 实验步骤 
1. 创建工程 
1) 打开QtCreator，如图1所示。

 选择File->New File or Project，然后在弹出的对话框中选择Other Project->Empty Qt project（如图2所示），然后进入下一步。 

 选择Qt版本，这里选择使用Qt4.7.1，取消对Qt in PATH的选择（如图4所示），然后进入下一步，完成新工程的创建（如图5所示）。

实现代码
Calcuulator.h代码：
#ifndef CALCULATOR_H

#define CALCULATOR_H

#include<QApplication>

#include<QDialog>

#include<QPushButton>

#include<QLineEdit>

class Calculator:public QDialog

{

Q_OBJECT

protected:

QLineEdit *lineEditor;

QPushButton *button_0;

QPushButton *button_1;

QPushButton *button_2;

QPushButton *button_3;

QPushButton *button_4;

QPushButton *button_5;

QPushButton *button_6;

QPushButton *button_7;

QPushButton *button_8;

QPushButton *button_9;

QPushButton *button_ce;

QPushButton *button_jia;

QPushButton *button_jian;

QPushButton *button_cheng;

QPushButton *button_chu;

QPushButton *button__;

QPushButton *button_dengyu;

int num1,num2,result; //

bool zhenghao; //

int mark; //

char fuhao; //

QString S; //

public:

Calculator();

private slots:

void button_0_clicked();

void button_1_clicked();

void button_2_clicked();

void button_3_clicked();

void button_4_clicked();

void button_5_clicked();

void button_6_clicked();

void button_7_clicked();

void button_8_clicked();

void button_9_clicked();

void button_ce_clicked();

void button_jia_clicked();

void button_jian_clicked();

void button_cheng_clicked();

void button_chu_clicked();

void button__clicked();

void button_dengyu_clicked();

};

#endif // CALCULATOR_H

Calculator.cpp代码：
#include<QLayout>

#include<QHBoxLayout>

#include<QVBoxLayout>

#include<QLineEdit>

#include<cmath>

#include"calculator.h"

Calculator::Calculator()

{

num1=0;

num2=0;

result=0;

zhenghao=true;

mark=1;

lineEditor=new QLineEdit("0");

S="";

button_0=new QPushButton("0");

button_1=new QPushButton("1");

button_2=new QPushButton("2");

button_3=new QPushButton("3");

button_4=new QPushButton("4");

button_5=new QPushButton("5");

button_6=new QPushButton("6");

button_7=new QPushButton("7");

button_8=new QPushButton("8");

button_9=new QPushButton("9");

button_ce=new QPushButton("CE");

button_cheng=new QPushButton("*");

button_jia=new QPushButton("+");

button_jian=new QPushButton("-");

button_chu=new QPushButton("/");

button__=new QPushButton("+/-");

button_dengyu=new QPushButton("=");

QHBoxLayout *Hl1=new QHBoxLayout;

QHBoxLayout *Hl2=new QHBoxLayout;

QHBoxLayout *Hl3=new QHBoxLayout;

QHBoxLayout *Hl4=new QHBoxLayout;

QHBoxLayout *Hl5=new QHBoxLayout;

Hl1->addWidget(lineEditor);

Hl1->addWidget(button_ce);

Hl2->addWidget(button_1);

Hl2->addWidget(button_2);

Hl2->addWidget(button_3);

Hl2->addWidget(button_jia);

Hl3->addWidget(button_4);

Hl3->addWidget(button_5);

Hl3->addWidget(button_6);

Hl3->addWidget(button_jian);

Hl4->addWidget(button_7);

Hl4->addWidget(button_8);

Hl4->addWidget(button_9);

Hl4->addWidget(button_cheng);

Hl5->addWidget(button__);

Hl5->addWidget(button_0);

Hl5->addWidget(button_dengyu);

Hl5->addWidget(button_chu);

QVBoxLayout *V1=new QVBoxLayout;

V1->addLayout(Hl1);

V1->addLayout(Hl2);

V1->addLayout(Hl3);

V1->addLayout(Hl4);

V1->addLayout(Hl5);

connect(button_0,SIGNAL(clicked()),this,SLOT(button_0_clicked()));

connect(button_1,SIGNAL(clicked()),this,SLOT(button_1_clicked()));

connect(button_2,SIGNAL(clicked()),this,SLOT(button_2_clicked()));

connect(button_3,SIGNAL(clicked()),this,SLOT(button_3_clicked()));

connect(button_4,SIGNAL(clicked()),this,SLOT(button_4_clicked()));

connect(button_5,SIGNAL(clicked()),this,SLOT(button_5_clicked()));

connect(button_6,SIGNAL(clicked()),this,SLOT(button_6_clicked()));

connect(button_7,SIGNAL(clicked()),this,SLOT(button_7_clicked()));

connect(button_8,SIGNAL(clicked()),this,SLOT(button_8_clicked()));

connect(button_9,SIGNAL(clicked()),this,SLOT(button_9_clicked()));

connect(button_jia,SIGNAL(clicked()),this,SLOT(button_jia_clicked()));

connect(button_jian,SIGNAL(clicked()),this,SLOT(button_jian_clicked()));

connect(button_cheng,SIGNAL(clicked()),this,SLOT(button_cheng_clicked()));

connect(button_chu,SIGNAL(clicked()),this,SLOT(button_chu_clicked()));

connect(button_dengyu,SIGNAL(clicked()),this,SLOT(button_dengyu_clicked()));

connect(button_ce,SIGNAL(clicked()),this,SLOT(button_ce_clicked()));

connect(button__,SIGNAL(clicked()),this,SLOT(button__clicked()));

setLayout(V1);

}

void Calculator::button_0_clicked()

{

S+="0";

lineEditor->setText(S);

if(mark==1){

num1=num1*10+0;

}else{

num2=num2*10;

}

}

void Calculator::button_1_clicked(){

S+="1";

lineEditor->setText(S);

if(mark==1){

if(zhenghao){

num1=num1*10+1;

}else{

num1=num1*10-1;

}

}else{

if(zhenghao){

num2=num2*10+1;

}else{

num2=num2*10-1;

}

}

}

void Calculator::button_2_clicked(){

S+="2";

lineEditor->setText(S);

if(mark==1){

if(zhenghao){

num1=num1*10+2;

}else{

num1=num1*10-2;

}

}else{

if(zhenghao){

num2=num2*10+2;

}else{

num2=num2*10-2;

}

}

}

void Calculator::button_3_clicked(){

S+="3";

lineEditor->setText(S);

if(mark==1){

if(zhenghao){

num1=num1*10+3;

}else{

num1=num1*10-3;

}

}else{

if(zhenghao){

num2=num2*10+3;

}else{

num2=num2*10-3;

}

}

}

void Calculator::button_4_clicked(){

S+="4";

lineEditor->setText(S);

if(mark==1){

if(zhenghao){

num1=num1*10+4;

}else{

num1=num1*10-4;

}

}else{

if(zhenghao){

num2=num2*10+4;

}else{

num2=num2*10-4;

}

}

}

void Calculator::button_5_clicked(){

S+="5";

lineEditor->setText(S);

if(mark==1){

if(zhenghao){

num1=num1*10+5;

}else{

num1=num1*10-5;

}

}else{

if(zhenghao){

num2=num2*10+5;

}else{

num2=num2*10-5;

}

}

}

void Calculator::button_6_clicked(){

S+="6";

lineEditor->setText(S);

if(mark==1){

if(zhenghao){

num1=num1*10+6;

}else{

num1=num1*10-6;

}

}else{

if(zhenghao){

num2=num2*10+6;

}else{

num2=num2*10-6;

}

}

}

void Calculator::button_7_clicked(){

S+="7";

lineEditor->setText(S);

if(mark==1){

if(zhenghao){

num1=num1*10+7;

}else{

num1=num1*10-7;

}

}else{

if(zhenghao){

num2=num2*10+7;

}else{

num2=num2*10-7;

}

}

}

void Calculator::button_8_clicked(){

S+="8";

lineEditor->setText(S);

if(mark==1){

if(zhenghao){

num1=num1*10+8;

}else{

num1=num1*10-8;

}

}else{

if(zhenghao){

num2=num2*10+8;

}else{

num2=num2*10-8;

}

}

}

void Calculator::button_9_clicked(){

S+="9";

lineEditor->setText(S);

if(mark==1){

if(zhenghao){

num1=num1*10+9;

}else{

num1=num1*10-9;

}

}else{

if(zhenghao){

num2=num2*10+9;

}else{

num2=num2*10-9;

}

}

}

void Calculator::button_jia_clicked(){

S+="+";

lineEditor->setText(S);

zhenghao=true;

fuhao='+';

mark=2;

}

void Calculator::button_jian_clicked(){

S+="-";

lineEditor->setText(S);

zhenghao=true;

fuhao='-';

mark=2;

}

void Calculator::button_cheng_clicked(){

S+="*";

lineEditor->setText(S);

zhenghao=true;

fuhao='*';

mark=2;

}

void Calculator::button_chu_clicked(){

S+="/";

lineEditor->setText(S);

zhenghao=true;

fuhao='/';

mark=2;

}

void Calculator::button__clicked(){

S+="-";

lineEditor->setText(S);

zhenghao=false;

}

void Calculator::button_dengyu_clicked(){

S+="=";

// lineEditor->setText(S);

switch(fuhao){

case '+':result=num1+num2;break;

case '-':result=num1-num2;break;

case '*':result=num1*num2;break;

case '/':if(num2)result=num1/num2;break;

}

int i=0;

int result1=result;

while(result1){

i++;

result1/=10;

}

for(;i;i--){

S+=(result/(int)pow(10,i-1)+'0');

result%=(int)pow(10,i-1);

}

lineEditor->setText(S);

zhenghao=true;

num1=num2=0;

mark=1;

S="";

}

void Calculator::button_ce_clicked()

{

zhenghao=false;

S="";

lineEditor->setText("0");

num1=num2=0;

mark=1;

}

Main代码：
#include"calculator.h"

int main(int argc,char *argv[])

{

QApplication app(argc,argv);

Calculator cal;

cal.show();

return app.exec();

}

运行结果

 四、总结
通过计算器设计，学到了利用Qt设计简单窗口应用程序的的方法，初步了解了使用QT工具编写窗口程序的新颖，了解了槽和信号等基本知识，学会了如何使用新工具（Qt）帮助程序开发。