QT 不规则窗口求助 [复制链接]

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_OBJECT
public:
    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！！