QT：图片按钮（改进版）

之前我写过一个可以直接显示图片的Button: http://blog.csdn.net/aaa20090987/article/details/6789380

当时为了方便，直接用QFrame作为它的基类，结果（布局，使用等）十分不方便，

还是老老实实地用 QAbstractButton 作为基类，再用paintEvent来画图吧

//tqt.h#ifndef TQT_H_#define TQT_H_#include <QtGui>#include <QtCore>class PictureButton : public QAbstractButton{Q_OBJECTprivate:QPixmap pixmap;protected:virtual void paintEvent(QPaintEvent *event);virtual QSize sizeHint() const;public:PictureButton(const QString &path, QWidget *parent=0);PictureButton(QWidget *parent = 0);~PictureButton();void setPixmap(const QString &path);};class Widget : public QWidget{Q_OBJECTprivate:QLabel *label;PictureButton *prevButton;PictureButton *nextButton;int num;public:Widget(QWidget *parent = 0);~Widget();public slots:void ClickedPrevButton();void ClickedNextButton();};#endif//tqt.cpp#include "tqt.h"PictureButton::PictureButton(const QString &path, QWidget *parent/* =0 */): QAbstractButton(parent){setPixmap(path);setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);}PictureButton::PictureButton(QWidget *parent /* = 0 */): QAbstractButton(parent){setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);}PictureButton::~PictureButton(){}void PictureButton::paintEvent(QPaintEvent *event){QPainter painter(this);painter.drawPixmap(0, 0, width(), height(), pixmap);}QSize PictureButton::sizeHint() const {return pixmap.size();}void PictureButton::setPixmap(const QString &path){pixmap.load(path);update();}Widget::Widget(QWidget *parent) : QWidget(parent){num = 0;label = new QLabel("0", this);//prev.jpg和next.jpg是当前文件夹中的两张JPG图片prevButton = new PictureButton("prev.jpg", this);nextButton = new PictureButton("next.jpg", this);QHBoxLayout *subLayout = new QHBoxLayout;QVBoxLayout *layout = new QVBoxLayout;subLayout->addWidget(prevButton);subLayout->addWidget(nextButton);layout->addWidget(label);layout->addLayout(subLayout);setLayout(layout);setWindowTitle("Widget");resize(200, 200);connect(prevButton, SIGNAL(clicked()), this, SLOT(ClickedPrevButton()));connect(nextButton, SIGNAL(clicked()), this, SLOT(ClickedNextButton()));}Widget::~Widget(){}void Widget::ClickedPrevButton(){num--;label->setText(QString::number(num));}void Widget::ClickedNextButton(){num++;label->setText(QString::number(num));}//main.cpp#include "tqt3.h"int main(int argc, char *argv[]){QApplication a(argc, argv);Widget w;w.show();return a.exec();}

注意：这个程序是用来研究的（或者说是玩的），如果要在按钮上加图片的话，直接用QToolButton就可以了