请教 QT编程问题

denixleen

源代码如下:
#include <qapplication.h>
#include <qsignalmapper.h>
#include <qstring.h>
#include <qpushbutton.h>
#include <qlayout.h>

class Keypad : public QWidget
   {
       Q_OBJECT
   public:
       Keypad(QWidget *parent = 0);
   signals:
       void digitClicked(int digit);
   private:
       void createLayout();
       QPushButton *buttons[10];
   };

Keypad::Keypad(QWidget *parent)
       : QWidget(parent)
   {
       QSignalMapper *signalMapper = new QSignalMapper(this);
       connect(signalMapper, SIGNAL(mapped(int)), this, SIGNAL(digitClicked(int)));       
       for (int i = 0; i < 10; ++i) {
           QString text = QString::number(i);
           buttons = new QPushButton(text, this);
           signalMapper->setMapping(buttons, i);
           connect(buttons, SIGNAL(clicked()), signalMapper, SLOT(map()));        
       }
   
       createLayout();
   }

void Keypad::createLayout()
   {
       QGridLayout *layout = new QGridLayout(this, 3, 4);
       layout->setMargin(6);
       layout->setSpacing(6);
       for (int i = 0; i < 9; ++i)
           layout->addWidget(buttons[i + 1], i / 3, i % 3);
       layout->addWidget(buttons[0], 3, 1);
   }

int main(int argc,char **argv)
{
    QApplication a(argc,argv);
    Keypad k;
    a.setMainWidget( &k );
    k.show();
    return a.exec();
}

然后,
qmake -project
qmake
make

编译信息如下:
g++ -c -pipe -Wall -W -O2  -DQT_NO_DEBUG -I/root/Trolltech/qtopia-free-2.1.1-debug/mkspecs/linux-g++ -I. -I. -I/root/Trolltech/qt-2.3.10/include -o mapper.o mapper.cpp
g++ -Wl,-rpath,/root/Trolltech/qt-2.3.10/lib -o mapper mapper.o   -L/root/Trolltech/qt-2.3.10/lib -L/usr/X11R6/lib -lqt -lXext -lX11 -lm
mapper.o(.text+0x1d): In function `Keypad::Keypad[not-in-charge](QWidget*)':
: undefined reference to `vtable for Keypad'
mapper.o(.text+0x23): In function `Keypad::Keypad[not-in-charge](QWidget*)':
: undefined reference to `vtable for Keypad'
mapper.o(.text+0x18d): In function `Keypad::Keypad[in-charge](QWidget*)':
: undefined reference to `vtable for Keypad'
mapper.o(.text+0x193): In function `Keypad::Keypad[in-charge](QWidget*)':
: undefined reference to `vtable for Keypad'
mapper.o(.text+0x3f5): In function `main':
: undefined reference to `vtable for Keypad'
mapper.o(.text+0x3ff): more undefined references to `vtable for Keypad' follow
collect2: ld returned 1 exit status
make: *** [mapper] Error 1

请问怎么回事?

denixleen

代码有问题么?
我的qte是 ./configure -debug -qvfb -depths 4,8,16,32 -keypad-mode -system-jpeg -gif
选择everything
make的

cavendish

不知道你的程序打算做什么
连点介绍都没有么？

huales

you can try to split your code into a cpp file and a header file,
and then compile, it will work.

jackzheng2002

[quote:748c5c7684="huales"]you can try to split your code into a cpp file and a header file,
and then compile, it will work.[/quote]

And the reasons...