我有这段代码。我试过的是将QGraphicsScene
子类化为重新实现它的keyPressEvent()
方法。我必须选择这种特殊的实现方式(特别是typedef
部分)为此,要解决与代码其他部分的兼容性问题。
keypress.h
#include <QWidget>
#include <QGraphicsScene>
#include <QGraphicsView>
class Canvas;
typedef struct{
int id;
int pid;
Canvas *qgc;
}scene;
class Canvas: public QGraphicsScene {
private:
scene *gc;
public:
Canvas(Scene* gc, QWidget *parent=0);
protected:
void keyPressEvent(QKeyEvent *e);
};
keypress.cpp
#include <QApplication>
#include <QKeyEvent>
#include "keypress.h"
Canvas::Canvas( Scene* gc, QWidget *parent)
: QGraphicsScene(parent)
{
this->gc=gc;
}
void Canvas::keyPressEvent(QKeyEvent *event)
{
if (event->key() == Qt::Key_Escape) {
qApp->quit();
}
}
的main.cpp
#include <QApplication>
#include "keypress.h"
#include <QGraphicsView>
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
Scene *s;
Canvas *canvas=new Canvas(s);
canvas->addText("Hello");
QGraphicsView view(canvas);
view.show();
return app.exec();
}
每当我尝试编译此程序时,我都会收到错误
In file included from keypress.cpp:4:
keypress.h:29: error: expected ‘)’ before ‘*’ token
keypress.cpp:6: error: expected ‘)’ before ‘*’ token
make: *** [keypress.o] Error 1
我的代码中有什么问题?