QT 不规则窗口求助

[weixin_38076068]

下面内容是Linux 窗口程序设计一书中关于QT 不规则窗口程序部分请大家帮忙看看为什么我使用Qt4.7.0编译成功后却没有显示？？//头文件部分#ifndef SHAPEWIDGET_H#define SHAPEWIDGET_H#include <QtGui>class QPoint;class ShapeWidget : public QWidget{    Q_OBJECTpublic:    ShapeWidget(QWidget *parent=0);protected:    void mousePressEvent(QMouseEvent *);    void mouseMoveEvent(QMouseEvent *);    void paintEvent(QPaintEvent *);private:    QPoint dragPosition;    //QPainterPath path;    QPainterPath pix;    QPalette palette;    QWidget *frame;};#endif // SHAPEWIDGET_H//功能函数实现#include "shapewidget.h"#include "ui_shapewidget.h"#include <QBitmap>#include <QPicture>#include "shapewidget.h"ShapeWidget::ShapeWidget(QWidget *parent)    : QWidget(parent,Qt::FramelessWindowHint){    QPixmap pix;    pix.load(":/images/tux.png",0,Qt::AvoidDither|Qt::ThresholdDither|Qt::ThresholdAlphaDither);    resize(pix.size());    setMask(pix.mask());}void ShapeWidget::mousePressEvent(QMouseEvent * event){    if (event->button() == Qt::LeftButton)    {         dragPosition = event->globalPos() - frameGeometry().topLeft();         event->accept();    }    if (event->button() == Qt::RightButton)    {         close();    }}void ShapeWidget::mouseMoveEvent(QMouseEvent * event){    if (event->buttons() & Qt::LeftButton)    {         move(event->globalPos() - dragPosition);         event->accept();    }}void ShapeWidget::paintEvent(QPaintEvent *){    QPainter painter(this);    painter.drawPixmap(0,0,QPixmap(":/tux.png"));}//main 函数#include <QApplication>#include "shapewidget.h"int main(int argc, char * argv[]){    QApplication app(argc,argv);    ShapeWidget shape;    //app.setMainWidget(&shape);    shape.show();    return app.exec();}请大家帮我看看，先谢了！！