Dialog::Dialog(QWidget *parent) :QDialog(parent),ui(new Ui::Dialog)

{

    ui->setupUi(this);

    ui->label->setScaledContents(true);

    gif = new QMovie(":/resource/a.gif");

    ui->label->setMovie(gif);

    gif->start();

}
一定要将QLabel的setScaledContents属性设置true，否则GIF不会动