【发布时间】：2014-03-14 02:38:37
【问题描述】：
编辑
当程序在我的 dialog.cpp 中启动时，我最初会创建所有对象，并将所有 QPixmap 存储在一个数组中，然后从它们中随机选择一个。我想传递给我的 maintargets 类并在场景中绘制的随机 QPixmap（它也在 dialog.cpp 中创建）。
// 对话框.cpp
#include "dialog.h"
#include "scene.h"
#include "ui_dialog.h"
#include "instructions.h"
#include "settings.h"
#include "highscore.h"
#include "maintargets.h"
#include <stdlib.h>
Dialog::Dialog(QWidget *parent) :
QDialog(parent),
ui(new Ui::Dialog)
{
ui->setupUi(this);
// Create and configure scene
scene = new Scene;
scene->setBackgroundBrush(Qt::black);
scene->setItemIndexMethod(QGraphicsScene::NoIndex);
ui->graphicsView->setScene(scene);
scene->setSceneRect(-200, -150, 400, 300);
ui->graphicsView->setMouseTracking(true);
QPixmap tankbase1(":/images/tankbase.jpg");
ui->tankbaseplay1->setPixmap(tankbase1);
//Store targets in array and random generator
index = 0;
main_targets[0] = QPixmap(":images/darkbluelogo.jpg)");
main_targets[1] = QPixmap(":images/graylogo.jpg");
main_targets[2] = QPixmap(":images/lightbluelogo.jpg");
main_targets[3] = QPixmap(":images/limE.jpg");
main_targets[4] = QPixmap(":images/pink.jpg");
main_targets[5] = QPixmap(":images/purple.jpg");
main_targets[6] = QPixmap(":images/redlogo.jpg");
main_targets[7] = QPixmap(":images/yellow.jpg");
main_targets[8] = QPixmap(":images/brown.jpg");
index = qrand((index % 9) + 1);
//scene->addItem(main_targets[index]);
//Timer for scene advancement
QTimer *timer = new QTimer();
QObject::connect(timer, SIGNAL(timeout()), scene, SLOT(advance()));
timer->start(100);
}
Dialog::~Dialog()
{
delete ui;
}
//maintargets.h
#ifndef MAINTARGETS_H
#define MAINTARGETS_H
#include "dialog.h"
#include <QGraphicsItem>
#include <QGraphicsScene>
#include <QPainter>
#include <QRect>
class MainTargets : public QGraphicsScene
{
public:
MainTargets();
QRectF boundingRect() const;
QPainterPath shape() const;
void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
protected:
void advance(int step);
private:
qreal dx, dy;
qreal x, y;
qreal w, h;
};
#endif // MAINTARGETS_H
//maintargets.cpp
#include "maintargets.h"
MainTargets::MainTargets()
{
dx = -0.005;
dy = 0.0;
x = 1.5;
y = 0.0;
w = 100.0;
h = 70.0;
}
QRectF MainTargets::boundingRect() const
{
qreal shift = 1;
return QRectF(-w/2 -shift, - h/2
- shift, w + shift, h + shift);
}
QPainterPath MainTargets::shape() const
{
QPainterPath path;
path.addRect(boundingRect());
return path;
}
void MainTargets::paint(QPainter *painter,
const QStyleOptionGraphicsItem *option,
QWidget *widget)
{
painter->drawPixmap(-w/2, -h/2, main_targets[index]);
}
void MainTargets::advance(int step)
{
if(step == 0) return;
x = x + dx;
y = y + dy;
setPos(mapToParent(x, y));
}
绘制后沿 x 方向移动。
【问题讨论】：
-
不就是 main_targets[index] 吗？
-
你是说 main_targets[index] 用于选择随机 QPixmap 吗？
-
是的，你写了
I want to pass the random QPixmap to another class，所以我假设你只是通过构造函数、getter 或其他方式将它传递给另一个类。它有什么问题？ -
你能展示一些传递参数的代码吗？就像我正在尝试做的那样？
-
不提供更多信息是不可能的。例如，您是否有权访问 dialog.cpp 中的 maintargets 对象，您可以在其中获取随机图像？
标签： c++ qt qtgui qgraphicsscene qpixmap