linux系统及编程基础课后答案(7)

#include #include #include #include #include #include class CWidget : public QWidget {

Q_OBJECT public:

CWidget(QWidget *parent=0, char *name=0); ~CWidget(); private:

QLineEdit *edit; QPushButton *button[16]; QVBoxLayout *mainLayout; QHBoxLayout *topLayout; QGridLayout *bottomLayout; int firstNum; int secondNum; int oper; protected slots: void setValue(); void setOper(); void calculate(); void clear(); protected:

virtual bool event(QEvent *e); private: void initialize(); void createForm(); void onClicked(int key); }; #endif

cwidget.cpp： #include \#define KEY_CLR \#define KEY_ADD \#define KEY_SUB \#define KEY_MUL \#define KEY_DIV \

#define KEY_EQ \#define KEY_0 \#define KEY_1 \#define KEY_2 \#define KEY_3 \#define KEY_4 \#define KEY_5 \#define KEY_6 \#define KEY_7 \#define KEY_8 \#define KEY_9 \#define BUTTONWIDTH 30 #define BUTTONHEIGHT 30 static char *buttontext[] = {

KEY_1,KEY_2,KEY_3,KEY_4, KEY_5,KEY_6,KEY_7,KEY_8,

KEY_9,KEY_ADD,KEY_SUB,KEY_MUL, KEY_DIV,KEY_EQ,KEY_CLR,KEY_0 };

CWidget::CWidget(QWidget *parent, char *name) {

initialize(); createForm(); }

CWidget::~CWidget() {

delete edit; delete *button; delete mainLayout; delete topLayout; delete bottomLayout; }

void CWidget::calculate() {

switch(oper) {

case Qt::Key_Plus:

firstNum += secondNum;break; case Qt::Key_Minus:

firstNum -= secondNum;break; case Qt::Key_Asterisk: firstNum *= secondNum;break; case Qt::Key_Slash:

firstNum /= secondNum;break; default:

firstNum = firstNum; }

edit->setText(QString::number(firstNum)); }

void CWidget::setValue() {

QString tempStr; tempStr = edit->text();

if(tempStr.length() < edit->maxLength()) tempStr += ((QPushButton *)sender())->text(); else {

QMessageBox::information( this, tr(\ }

if(-1==oper) {

firstNum = tempStr.toInt();

edit->setText(QString::number(firstNum)); } else {

secondNum = tempStr.toInt();

edit->setText(QString::number(secondNum)); } }

void CWidget::setOper() {

QString str=((QPushButton *)sender())->text(); if(str == \

onClicked(Qt::Key_Plus); else if(str == \

onClicked(Qt::Key_Minus); else if(str == \

onClicked(Qt::Key_Asterisk); else if(str == \

onClicked(Qt::Key_Slash); else if(str == \ calculate(); }

void CWidget::clear() {

edit->clear();

edit->setText(tr(\ initialize(); }

void CWidget::initialize() {

firstNum = 0; secondNum = 0; oper = -1; }

void CWidget::createForm() {

setMinimumSize(80,200); setMaximumSize(80,200);

mainLayout = new QVBoxLayout(this,20); topLayout = new QHBoxLayout(mainLayout,30); edit = new QLineEdit(this,\ edit->setAlignment(Qt::AlignRight); edit->setMaxLength(9); edit->setText(tr(\ edit->setReadOnly(true); topLayout->addWidget(edit);

bottomLayout = new QGridLayout(mainLayout,4,4,10); int n;

for(int r=0; r<3; r++) for(int c=0; c<3; c++) {

n = c+3*r;

button[n] = new QPushButton(buttontext[n],this,buttontext[n]); button[n]->setFixedSize(BUTTONWIDTH,BUTTONHEIGHT); bottomLayout->addWidget(button[n],r,c);

connect(button[n],SIGNAL(clicked()),this,SLOT(setValue())); }

button[9] = new QPushButton(buttontext[9],this,buttontext[9]); button[9]->setFixedSize(BUTTONWIDTH,BUTTONHEIGHT); bottomLayout->addWidget(button[9],0,3);

connect(button[9],SIGNAL(clicked()),this,SLOT(setOper()));

button[10] = new QPushButton(buttontext[10],this,buttontext[10]); button[10]->setFixedSize(BUTTONWIDTH,BUTTONHEIGHT); bottomLayout->addWidget(button[10],1,3);

connect(button[10],SIGNAL(clicked()),this,SLOT(setOper()));

button[11] = new QPushButton(buttontext[11],this,buttontext[11]); button[11]->setFixedSize(BUTTONWIDTH,BUTTONHEIGHT); bottomLayout->addWidget(button[11],2,3);

connect(button[11],SIGNAL(clicked()),this,SLOT(setOper()));

button[12] = new QPushButton(buttontext[12],this,buttontext[12]); button[12]->setFixedSize(BUTTONWIDTH,BUTTONHEIGHT); bottomLayout->addWidget(button[12],3,3);

connect(button[12],SIGNAL(clicked()),this,SLOT(setOper()));

button[13] = new QPushButton(buttontext[13],this,buttontext[13]); button[13]->setFixedSize(BUTTONWIDTH,BUTTONHEIGHT); bottomLayout->addWidget(button[13],3,2);

connect(button[13],SIGNAL(clicked()),this,SLOT(calculate()));

button[14] = new QPushButton(buttontext[14],this,buttontext[14]); button[14]->setFixedSize(BUTTONWIDTH,BUTTONHEIGHT); bottomLayout->addWidget(button[14],3,1);

connect(button[14],SIGNAL(clicked()),this,SLOT(clear()));

button[15] = new QPushButton(buttontext[15],this,buttontext[14]); button[15]->setFixedSize(BUTTONWIDTH,BUTTONHEIGHT); bottomLayout->addWidget(button[15],3,0);

connect(button[15],SIGNAL(clicked()),this,SLOT(setValue())); }

bool CWidget::event(QEvent *e) {

if(e->type() == QEvent::KeyPress) {

QKeyEvent *KeyEvent = static_cast(e); switch(KeyEvent->key()) {

case Qt::Key_Plus:

onClicked(Qt::Key_Plus);break; case Qt::Key_Minus:

onClicked(Qt::Key_Minus);break; case Qt::Key_Asterisk:

onClicked(Qt::Key_Asterisk);break; case Qt::Key_Slash:

onClicked(Qt::Key_Slash);break; case Qt::Key_Equal: calculate();break; } }

return QWidget::event(e); }

void CWidget::onClicked(int key) {

edit->clear();

edit->setText(tr(\ oper = key; }