今天上QT課程課堂上所寫的簡易坦克車移動範例

昨天開始上QT第一天，今天是第二天了，已經上到各種 Event Process 部分，也在課堂上實際撰寫一支小範例，這一個範例是用 specific KeyPress event handler，模擬按上下左右鍵，可以移動坦克車。

執行畫面如下:

補充一點，拜QT Designer的方便，寫這一整支程式可能僅需花費約10分鐘左右喔^^，程式碼如下:

k.h 檔:

/*
*k.h - A QT program header file.
*Authored by YiHua,Chiang
*EMail: microcyh@seed.net.tw
*CYH' Blog: http://tw.myblog.yahoo.com/yh-chiang
*
*Copyright(C) 2009/01/07 http://tw.myblog.yahoo.com/yh-chiang
*
*This program is free software. you can redistribute it and/or
*modify it under the terms of the GNU Public License as published
*by the Free Software Foundation: version 2 of the license.
*
*This program is distributed in the hope that it will be useful,
*but WITHOUT ANY WARRANTY; without even the implied warranty of
*MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*GNU Lesser Public License for more details.
*/
#include
#include

#include "ui_k.h"

class myGUI : public QWidget, public Ui::Form
{
   Q_OBJECT
public:
    myGUI(QWidget *parent = 0);
    void keyPressEvent( QKeyEvent * );
};

main.cpp 檔:

/*
*main.cpp - A QT program file.
*Authored by YiHua,Chiang
*EMail: microcyh@seed.net.tw
*CYH' Blog: http://tw.myblog.yahoo.com/yh-chiang
*
*Copyright(C) 2009/01/07 http://tw.myblog.yahoo.com/yh-chiang
*
*This program is free software. you can redistribute it and/or
*modify it under the terms of the GNU Public License as published
*by the Free Software Foundation: version 2 of the license.
*
*This program is distributed in the hope that it will be useful,
*but WITHOUT ANY WARRANTY; without even the implied warranty of
*MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*GNU Lesser Public License for more details.
*/
#include
#include
#include
#include "k.h"
int dir = 0;  // o is up   1 is down   2 is left   3 is right
myGUI::myGUI(QWidget *parent):QWidget( parent )
{
  setupUi( this );
  dir = 0;
}
void myGUI::keyPressEvent( QKeyEvent *event )
{
  int x=label->x(); int y=label->y(); int w=label->width(); int h=label->height();
  int fw=this->width(); int fh=this->height();
  switch( event->key() )
  {
    case Qt::Key_Up:
      {
        if( dir != 0 )
        {
          label->setPixmap( QPixmap(QString::fromUtf8("qt_up.PNG")) );
          dir = 0;
        }
        y = y -2;
        if( y <=0 )
          y = 0;
      }break;
    case Qt::Key_Down:
      {
        if( dir != 1 )
        {
          label->setPixmap( QPixmap(QString::fromUtf8("qt_dw.PNG")) );
          dir = 1;
        }
        y = y + 2;
        if( y+h >= fh )
          y = fh-h;
      }break;
    case Qt::Key_Left:
      {
        if( dir != 2 )
        {
          label->setPixmap( QPixmap(QString::fromUtf8("qt_lt.PNG")) );
          dir = 2;
        }
        x = x -2;
        if( x <= 0 )
          x = 0;
      }break;
    case Qt::Key_Right:
      {
        if( dir != 3 )
        {
          label->setPixmap( QPixmap(QString::fromUtf8("qt_rt.PNG")) );
          dir = 3;
        }
        x = x + 2;
        if( x+w>= fw )
          x = fw - w;
      }break;
  }
  label->setGeometry( x, y, w, h );
}
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    myGUI *form = new myGUI;
    form->show();
    return app.exec();
}

ui_k.h 檔:

/********************************************************************************
** Form generated from reading ui file 'k.ui'
**
** Created: Wed Jan 7 19:17:54 2009
**      by: Qt User Interface Compiler version 4.4.3
**
** WARNING! All changes made in this file will be lost when recompiling ui file!
********************************************************************************/

#ifndef UI_K_H
#define UI_K_H

#include
#include
#include
#include
#include
#include

QT_BEGIN_NAMESPACE

class Ui_Form
{
public:
    QLabel *label;

    void setupUi(QWidget *Form)
    {
    if (Form->objectName().isEmpty())
        Form->setObjectName(QString::fromUtf8("Form"));
    Form->resize(276, 190);
    label = new QLabel(Form);
    label->setObjectName(QString::fromUtf8("label"));
    label->setGeometry(QRect(90, 85, 38, 38));
    QSizePolicy sizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);
    sizePolicy.setHorizontalStretch(0);
    sizePolicy.setVerticalStretch(0);
    sizePolicy.setHeightForWidth(label->sizePolicy().hasHeightForWidth());
    label->setSizePolicy(sizePolicy);
    label->setAutoFillBackground(false);
    label->setStyleSheet(QString::fromUtf8(""));
    label->setPixmap( QPixmap(QString::fromUtf8("qt_up.PNG")) );
    label->setScaledContents(true);
    label->setAlignment(Qt::AlignCenter);

    retranslateUi(Form);

    QMetaObject::connectSlotsByName(Form);
    } // setupUi

    void retranslateUi(QWidget *Form)
    {
    Form->setWindowTitle(QApplication::translate("Tank game", "Tank game", 0, QApplication::UnicodeUTF8));
    label->setText(QString());
    Q_UNUSED(Form);
    } // retranslateUi

};

namespace Ui {
    class Form: public Ui_Form {};
} // namespace Ui

QT_END_NAMESPACE

#endif // UI_K_H