Qt4 C++ 简易计算器.doc

成都理工大学Qt课程设计报告Qt课程设计报告起止日期: 2011年9月-2012年1月院系名称：信息科学与技术学院软件工程系指导老师:xxxx班 级：xxxxx学 号：xxxxx姓 名：xxx1. 源代码：button.h#ifndef BUTTON_H#define BUTTON_H #include class Button : public QToolButton Q_OBJECT public: Button(const QString &text, QWidget *parent = 0); QSize sizeHint() const; ; #endifButton.cpp#include #include button.h Button:Button(const QString &text, QWidget *parent) : QToolButton(parent) setSizePolicy(QSizePolicy:Expanding, QSizePolicy:Preferred); setText(text); QSize Button:sizeHint() const QSize size = QToolButton:sizeHint(); size.rheight() += 20; size.rwidth() = qMax(size.width(), size.height(); return size; Calculator.h#ifndef CALCULATOR_H#define CALCULATOR_H #include class QLineEdit; class Button; class Calculator : public QDialog Q_OBJECT public: Calculator(QWidget *parent = 0); private slots: void digitClicked(); void additiveOperatorClicked(); void multiplicativeOperatorClicked(); void equalClicked(); void pointClicked(); void backspaceClicked(); void clear(); void clearAll(); private: Button *createButton(const QString &text, const char *member); void abortOperation(); bool calculate(double rightOperand, const QString &pendingOperator); double sumInMemory; double sumSoFar; double factorSoFar; QString pendingAdditiveOperator; QString pendingMultiplicativeOperator; bool waitingForOperand; QLineEdit *display; enum NumDigitButtons = 10 ; Button *digitButtonsNumDigitButtons; ; #endifCalculator.cpp#include #include #include button.h#include calculator.hCalculator:Calculator(QWidget *parent) : QDialog(parent) sumInMemory = 0.0; sumSoFar = 0.0; factorSoFar = 0.0; waitingForOperand = true; display = new QLineEdit(0); display-setReadOnly(true); display-setAlignment(Qt:AlignRight); display-setMaxLength(15); QFont font = display-font(); font.setPointSize(font.pointSize() + 8); display-setFont(font); for (int i = 0; i NumDigitButtons; +i) digitButtonsi = createButton(QString:number(i), SLOT(digitClicked(); Button *pointButton = createButton(tr(.), SLOT(pointClicked();/定义点按钮 并且与槽函数 pointClicked()建立连接。 Button *backspaceButton = createButton(tr(setSizeConstraint(QLayout:SetFixedSize); mainLayout-addWidget(display, 0, 0, 1, 6); mainLayout-addWidget(backspaceButton, 1, 0,1,2); mainLayout-addWidget(clearAllButton, 1, 4,1,2); for (int i = 1; i addWidget(digitButtonsi, row, column); /在网格布局中添加控件 mainLayout-addWidget(digitButtons0, 5, 1); mainLayout-addWidget(pointButton, 5, 2); mainLayout-addWidget(divisionButton, 2, 4); mainLayout-addWidget(timesButton, 3, 4); mainLayout-addWidget(minusButton, 4, 4); mainLayout-addWidget(plusButton, 5, 3); mainLayout-addWidget(equalButton, 5, 4); setLayout(mainLayout); setWindowTitle(tr(Calculator);/实现这些槽函数void Calculator:digitClicked() Button *clickedButton = qobject_cast(sender(); int digitValue = clickedButton-text().toInt(); if (display-text() = 0 & digitValue = 0.0) return; if (waitingForOperand) display-clear(); waitingForOperand = false; display-setText(display-text() + QString:number(digitValue);void Calculator:additiveOperatorClicked() Button *clickedButton = qobject_cast(sender(); QString clickedOperator = clickedButton-text(); double operand = display-text().toDouble(); if (!pendingMultiplicativeOperator.isEmpty() if (!calculate(operand, pendingMultiplicativeOperator) abortOperation(); return; display-setText(QString:number(factorSoFar); operand = factorSoFar; factorSoFar = 0.0; pendingMultiplicativeOperator.clear(); if (!pendingAdditiveOperator.isEmpty() if (!calculate(operand, pendingAdditiveOperator) abortOperation(); return; display-setText(QString:number(sumSoFar); else sumSoFar = operand; pendingAdditiveOperator = clickedOperator; waitingForOperand = true;void Calculator:multiplicativeOperatorClicked() Button *clickedButton = qobject_cast(sender(); QString clickedOperator = clickedButton-text(); double operand = display-text().toDouble(); if (!pendingMultiplicativeOperator.isEmpty() if (!calculate(operand, pendingMultiplicativeOperator) abortOperation(); return; display-setText(QString:number(factorSoFar); else factorSoFar = operand; pendingMultiplicativeOperator = clickedOperator; waitingForOperand = true;void Calculator:equalClicked() double operand = display-text().toDouble(); if (!pendingMultiplicativeOperator.isEmpty() if (!calculate(operand, pendingMultiplicativeOperator) abortOperation(); return; operand = factorSoFar; factorSoFar = 0.0; pendingMultiplicativeOperator.clear(); if (!pendingAdditiveOperator.isEmpty() if (!calculate(operand, pendingAdditiveOperator) abortOperation(); return; pendingAdditiveOperator.clear(); else sumSoFar = operand; display-setText(QString:number(sumSoFar); sumSoFar = 0.0; waitingForOperand = true;void Calculator:pointClicked() if (waitingForOperand) display-setText(0); if (!display-text().contains(.) display-setText(display-text() + tr(.); waitingForOperand = false;void Calculator:backspaceClicked() if (waitingForOperand) return; QString text = display-text(); text.chop(1); if (text.isEmpty() text = 0; waitingForOperand = true; display-setText(text);void Calculator:clear() if (waitingForOperand) return; display-setText(0); waitingForOperand = true;void Calculator:clearAll() sumSoFar = 0.0; factorSoFar = 0.0; pendingAdditiveOperator.clear(); pendingMultiplicativeOperator.clear(); display-setText(0); waitingForOperand = true;/定义createButton函数 需要字符串参数 和 一个 字符指针/在此函数内连接信号与槽Button *Calculator:createButton(const QString &text, const char *member) Button *button = new Button(text); connect(button, SIGNAL(clicked(), this, member); return button;void Calculator:abortOperation() clearAll(); display-setText(tr(#);bool Calculator:calculate(double rightOperand, const QString &pendingOperator) if (pendingOperator = tr(+) sumSoFar += rightOperand; else if (pendingOperator = tr(-) sumSoFar -= rightOperand; else if (pendingOperator = tr(327) factorSoFar *= rightOperand; else if (pendingOperator = tr(367) if (rightOperand = 0.0) return false; factorSoFar /= rightOperand; return true;2 程序实现；1、对于界面设计 采用的网格布局作为主布局，然后使用其addWidget函数添加部件，最后实现了基本的简易计算机的界面界面如图所示：2.首先输入相应的要求输入的数据。在界面上，点击相应的按钮，信号会随着点击传递到相应的槽函数中，并实现函数的功能，经过处理得到相应的结果。并能够将结果输出。下面依次介绍按钮及所连接的槽函数相应的连接信号语句：Button *clearAllButton = createButton(tr(clearAll), SLOT(clearAll(); /用createButton函数定义除法按钮并且与除法槽函数建立 Button *divisionButton = createButton(tr(367), SLOT(multiplicativeOperatorClicked(); /定义乘法按钮 Button *timesButton = createButton(tr(327), SLOT(multiplicativeOperatorClicked(); /定义减法按钮 Button *minusButton = createButton(tr(-), SLOT(additiveOperatorClicked(); /定义加法按钮 Button *plusButton = createButton(tr(+), SLOT(additiveOperatorClicked(); /定义等号按钮Button *equalButton = createButton(tr(=), SLOT(equalClicked(); /实现代码 如下createButton函数为自