实验四Qt编写简单的计算器 - 图文(2)

图6

4) 添加文件calculator.h

在工程Calculator上面点击右键，然后点击Add New，选择添加C++ Header File（如图7所示），进入下一步后输入文件名calculator.h（如图8所示），然后完成文件的添加。

图7

图8

5) 添加文件calculator.cpp和main.cpp

与添加文件calculator.h的过程类似，只是在选择文件类型时选择为C++ Source File。完成后可以查看Calculator.pro文件的内容，整个工程的文件结构如图9所示。

图9

3. 计算器程序源代码的分析说明

1) 对calculator.h源代码的简要说明

#ifndef CALCULATOR_H

#define CALCULATOR_H //对calculator.h头文件的声明 #include//包含主窗体类 #include//包含按键类

#include//包含垂直布局器类 #include//包含水平布局器类 #include//包含显示框类

class Calculator : publicQWidget//计算器继承自主窗体类 {

Q_OBJECT //必须加上这句，如果要调用信号，槽函数的操作的话 public:

Calculator(); //计算器类的构造函数 ~Calculator(); //计算器类的析构函数

public slots: //定义各个按键按下后对应操作处理的槽函数 voidzeroButtonPress(); voidoneButtonPress(); voidtwoButtonPress(); voidthreeButtonPress(); voidfourButtonPress(); voidfiveButtonPress(); voidsixButtonPress(); voidsevenButtonPress(); voideightButtonPress(); voidnineButtonPress(); voidaddButtonPress(); voidsubButtonPress(); voidmulButtonPress(); voiddivButtonPress(); voidclearButtonPress(); voidequButtonPress();

private:

QLineEdit *operateEdit;//声明显示框

QPushButton *zeroButton;//声明数字按键1 QPushButton *oneButton; QPushButton *twoButton; QPushButton *threeButton; QPushButton *fourButton; QPushButton *fiveButton; QPushButton *sixButton; QPushButton *sevenButton; QPushButton *eightButton; QPushButton *nineButton;

QPushButton *clearButton;//声明运算符按键 QPushButton *addButton; QPushButton *subButton; QPushButton *divButton; QPushButton *mulButton; QPushButton *equButton;

QHBoxLayout *firstLayout;//声明水平布局器，该布局器主要对16个按键进行布局 QHBoxLayout *secondLayout; QHBoxLayout *thirdLayout; QHBoxLayout *fourthLayout;

QVBoxLayout *mainLayout;//声明垂直布局器，该布局器主要对主窗体上面的空间进行排布

QString input1;//计算器第一个运算操作数 QString input2;//计算器第二个运算操作数 char operate;//运算符 };

#endif// CALCULATOR_H

2) 对calculator.cpp源代码的简要说明 首先是构造函数的实现：

Calculator::Calculator() {

operateEdit = newQLineEdit(this);//初始化显示框 operateEdit->setReadOnly(true); //设置显示框为只读

operateEdit->setText(tr(\));//初始化显示框显示数据为0

zeroButton = newQPushButton;//初始化按键

zeroButton->setText(tr(\));//设置按键上显示的标签，以下对按键相关的操作类似

oneButton = newQPushButton; oneButton->setText(tr(\)); twoButton = newQPushButton; twoButton->setText(tr(\)); threeButton = newQPushButton; threeButton->setText(tr(\)); fourButton = newQPushButton; fourButton->setText(tr(\)); fiveButton = newQPushButton; fiveButton->setText(tr(\)); sixButton = newQPushButton; sixButton->setText(tr(\));

sevenButton = newQPushButton; sevenButton->setText(tr(\)); eightButton = newQPushButton; eightButton->setText(tr(\)); nineButton = newQPushButton; nineButton->setText(tr(\)); clearButton = newQPushButton; clearButton->setText(tr(\)); addButton = newQPushButton; addButton->setText(tr(\));