Qt 实现桌面雪花飘落代码

#include <time.h>

#ifdef Q_OS_LINUX
#include <X11/extensions/shape.h>
#endif
#ifdef Q_OS_WIN
#include <windows.h>
#endif

Widget::Widget(QWidget *parent) :
 QWidget(parent),
 ui(new Ui::Widget)
{
 ui->setupUi(this);
 setGeometry(0, 0, qApp->desktop()->width(), qApp->desktop()->height());
 setWindowFlags(windowFlags()
       |Qt::FramelessWindowHint //去边框
       |Qt::X11BypassWindowManagerHint //linux下脱离任务管理器
       |Qt::WindowStaysOnBottomHint //最低层显示
       |Qt::Tool //不在任务栏显示
     );
 setAttribute(Qt::WA_TranslucentBackground);
 setWindowState(Qt::WindowNoState //不激活
       |Qt::WindowFullScreen //全屏
       );
 setFocusPolicy(Qt::NoFocus);
 setWindowOpacity(WINDOW_OPACITY);
#ifdef Q_OS_LINUX
 XShapeCombineRectangles(QX11Info::display(), winId(), ShapeInput, 0,
        0, NULL, 0, ShapeSet, YXBanded);
#endif
#ifdef Q_OS_WIN
 SetWindowLong(winId(), GWL_EXSTYLE, GetWindowLong(winId(), GWL_EXSTYLE) |
      WS_EX_TRANSPARENT | WS_EX_LAYERED);
#endif
 int i=0;
 pixmapList[i++].load(":/snowIcons/11.png");
 pixmapList[i++].load(":/snowIcons/03.png");
 pixmapList[i++].load(":/snowIcons/06.png");
 pixmapList[i++].load(":/snowIcons/08.png");
 pixmapList[i++].load(":/snowIcons/10.png");
 pixmapList[i++].load(":/snowIcons/12.png");
 pixmapList[i++].load(":/snowIcons/13.png");
 pixmapList[i++].load(":/snowIcons/16.png");
 pixmapList[i++].load(":/snowIcons/17.png");
 pixmapList[i++].load(":/snowIcons/18.png");
 pixmapList[i++].load(":/snowIcons/19.png");

 for(i = 0; i < MAX_PICS; i++)
 {
  picLabel[i] = new QLabel(this);
  picLabel[i]->setGeometry(-128, -128, 64, 64);
 }
 startTimer(150);
}

Widget::~Widget()
{
 delete ui;
}

void Widget::timerEvent(QTimerEvent *e)
{
 const int timeinit = 10;
 static int timeCount = timeinit;
 static int initLabel = MAX_PICS;
 if(--timeCount <= 0)
 {
  qsrand(::time(NULL));
  timeCount = timeinit;
  if(initLabel > 0)
  {
   --initLabel;
   picLabel[initLabel]->move(0, -picLabel[initLabel]->height());
  }
 }
 FlashSnow();
}

void Widget::SetLabelBG(const QPixmap &pixmap, QLabel *label)
{
 if(!label || pixmap.isNull()) return;
 QPixmap map = pixmap.scaled(label->size());
 if(map.isNull()) return;
 label->setPixmap(map);
}

void Widget::FlashSnow()
{
 int i;
 for(i = 0; i < MAX_PICS; i++)
 {
  if(picLabel[i] == NULL) continue;
  if(picLabel[i]->y() == -picLabel[i]->height())
  {
   //resize label
   int size = (qrand()%64)+16;
   picLabel[i]->resize(size, size);

   //init place
   int x = (qrand()%this->width());
   picLabel[i]->move(x, 10-picLabel[i]->height());

   //repaint label's backgroud
   int imgId = (qrand()%MAX_PIXMAP);
   SetLabelBG(pixmapList[imgId], picLabel[i]);
  }
  else
  {
   //snow flow down
   WidgetFlowDown(picLabel[i]);
  }
 }
}

void Widget::WidgetFlowDown(QWidget *widget, bool bRandom)
{
 if(!widget) return;
 int downY = widget->y()+5;
 if(bRandom)
 {
  downY = widget->y()+qrand()%(this->height() - widget->y());
 }
 if(downY > (this->height())) downY = -widget->height();
 widget->move(widget->x(), downY);
}