From Gossip@caterpillar

Qt3 Gossip: QCanvas 類別 - QCanvasSprite 動畫播放

QCanvasSprite 可以根據一組給定的圖片進行連續的圖片播放，這組圖片是設定在QCanvasPixmapArray類別中，QCanvasPixmapArray中的圖片都是以索引來管理，我們可以使用setImage()方法來讀入圖片，我們使用setSequence()指定這組 QCanvasPixmapArray圖片給QCanvasSprite物件。

下面這個程式很簡單，示範如何使用QCanvasSprite進行動畫播放，畫面會有兩隻小毛蟲進行賽跑，不斷的一伸一縮並向右移動：

#include <qapplication.h>
#include <qcanvas.h>
#include <qimage.h>

class Caterpillar : public QCanvasSprite {
public:
    Caterpillar(QCanvas *canvas) : QCanvasSprite(0, canvas) {
        static QCanvasPixmapArray ani;
        // 讀入一組圖片
        ani.setImage(0, new QCanvasPixmap("cater1.jpg"));
        ani.setImage(1, new QCanvasPixmap("cater2.jpg"));
        // setup圖片組
        setSequence(&ani);
        // 循環播放
        setFrameAnimation(QCanvasSprite::Cycle);
    }
};

class View : public QCanvasView {
public:
    View(QCanvas& canvas) : QCanvasView(&canvas){
        canvas.resize(300, 200);
        setFixedSize(sizeHint());

        Caterpillar *cater1 = new Caterpillar(&canvas);
        cater1->move(250, 50);
        cater1->setVelocity(-1, 0);
        cater1->setZ(10);
        cater1->show();

        Caterpillar *cater2 = new Caterpillar(&canvas);
        cater2->move(250, 100);
        cater2->setVelocity(-1.5, 0);
        cater2->setZ(10);
        cater2->show();
     }
};

int main(int argc, char** argv) {
    QApplication app(argc, argv);

    QCanvas canvas(0, 0);

    canvas.setAdvancePeriod(500);  // 移動更新間隔:
    canvas.setDoubleBuffering(true); // double buffer
    View c(canvas);

    app.setMainWidget(&c);
    c.show();

    return app.exec();
}

下圖為執行的結果：