头文件：

#include <qpainter.h>
#define BTN_STATUX_OK_PNG		":/Resources/MainWindow/StatusSucceeded.png"

函数定义：

void drawButtonIcon(QPushButton*&btn, const QString&icon);

源代码：

void CCMainWindow::drawButtonIcon(QPushButton *& btn, const QString & icon)
{
	QPixmap pixmap(btn->size());	//这是画布
	pixmap.fill(Qt::transparent);	//透明填充
	QPixmap iconPixmap(icon);		//原片

	QPainter p(&pixmap);
	
	//绘画起点
	p.drawPixmap((pixmap.width() - iconPixmap.width()) / 2, (pixmap.height() - iconPixmap.height()) / 2, iconPixmap);

	btn->setIcon(pixmap);
	btn->setIconSize(btn->size());

}

函数调用：

void CCMainWindow::initButton()
{
	//状态按钮
	drawButtonIcon(ui.statusBtn, BTN_STATUX_OK_PNG);

}