Qt事件--数字时钟

实验：

1）用Timer显示时间

2）用Timer定时

3）鼠标左键按下控件可随意在桌面上拖动

main.cpp

#include <qapplication.h> #include "form2.h" int main( int argc, char ** argv ) { QApplication a( argc, argv ); Form2 w; w.show(); a.connect( &a, SIGNAL( lastWindowClosed() ), &a, SLOT( quit() ) ); return a.exec(); }

form2.cpp

/**************************************************************************** ** Form implementation generated from reading ui file 'form2.ui' ** ** Created by: The User Interface Compiler ($Id: qt/main.cpp 3.3.6 edited Aug 31 2005 $) ** ** WARNING! All changes made in this file will be lost! ****************************************************************************/ #include "form2.h" #include <qvariant.h> #include <qlcdnumber.h> #include <qlayout.h> #include <qtooltip.h> #include <qwhatsthis.h> #include <qimage.h> #include <qpixmap.h> #include<qtimer.h> #include<qdatetime.h> #include <qpoint.h> /* * Constructs a Form2 as a child of 'parent', with the * name 'name' and widget flags set to 'f'. * * The dialog will by default be modeless, unless you set 'modal' to * TRUE to construct a modal dialog. */ DigiClock::DigiClock(QWidget * parent, const char * name) : QLCDNumber(parent,name) { QPalette p = palette(); p.setColor(QPalette::Normal, QColorGroup::Background, Qt::blue); setPalette(p); QTimer *timer = new QTimer(this); connect(timer,SIGNAL(timeout()),SLOT(showTime())); timer->start(1000); showColon = true; showTime(); } void DigiClock::showTime() { QTime time = QTime::currentTime(); QString text = time.toString("hh:mm"); if(showColon) { text[2] = ':'; showColon = false; } else { text[2] = ' '; showColon = true; } display(text); } Form2::Form2( QWidget* parent, const char* name, bool modal, WFlags fl ) : QDialog( parent, name, modal, fl ) { setMouseTracking (true); if ( !name ) setName( "Form2" ); lCDNumber2 = new DigiClock( this, "lCDNumber2"); lCDNumber2->setGeometry( QRect( 0, 0, 370, 70 ) ); languageChange(); resize( QSize(369, 70).expandedTo(minimumSizeHint()) ); clearWState( WState_Polished ); LbuttonFlag = false; } /* * Destroys the object and frees any allocated resources */ Form2::~Form2() { // no need to delete child widgets, Qt does it all for us } /* * Sets the strings of the subwidgets using the current * language. */ void Form2::languageChange() { setCaption( tr( "Form2" ) ); } void Form2::mousePressEvent(QMouseEvent *e) { if(e->button()==QMouseEvent::LeftButton) { dragPositon = e->globalPos()-frameGeometry().topLeft(); LbuttonFlag = true; e->accept(); } } void Form2::mouseReleaseEvent(QMouseEvent * e) { LbuttonFlag = false; } void Form2::mouseMoveEvent(QMouseEvent *e) { if(LbuttonFlag) { move(e->globalPos()-dragPositon); qDebug("gx=%d,gy%d,x=%d,y=%d",e->globalX(),e->globalY(),dragPositon.x(),dragPositon.y()); e->accept(); } }