QPrinter printer;
printer.setPageSize(QPrinter::A4);
QPainter painter(&printer);
pixmap= new QPixmap();
pixmap= cprint->getpixmaplast();
QMatrix matrix;
matrix.rotate(90);
QPixmap *img1= new QPixmap;
*img1=pixmap->transformed(matrix);
QRect rect = painter.viewport();
QPixmap image = img1->scaled(rect.size());
QSize size = image.size();
size.scale(rect.size(), Qt::KeepAspectRatio);
painter.setWindow(image.rect());
painter.drawPixmap(0,0,image);
可以直接打印横向图片这里使用的是a4纸大小
如果需要预览
void Destop::Rele_cprint_print()
{
QPrinter printer(QPrinter::HighResolution);
plotPic(&printer);
QPrintPreviewDialog preview(&printer,0);/* 打印预览 */
/**
* QPrintPreviewDialog类提供了一个打印预览对话框,里面功能比较全,
* paintRequested(QPrinter *printer)是系统提供的,
* 当preview.exec()执行时该信号被触发,
* plotPic(QPrinter *printer)是用户自定义的槽函数,图像的绘制就在这个函数里。
*/
connect(&preview, SIGNAL(paintRequested(QPrinter *)),this,SLOT(plotPic(QPrinter *)));
preview.exec(); /* 等待预览界面退出 */
}
void Destop::plotPic(QPrinter *printer)
{
QPainter painter(printer);
pixmap= new QPixmap();
QImage *img = new QImage;
img->load(strName);
QPixmap image = QPixmap::fromImage(*img);
QRect rect = painter.viewport();
QSize size = pixmap->size();
size.scale(rect.size(), Qt::KeepAspectRatio);//此处保证图片显示完整
painter.setViewport(rect.x(), rect.y(),size.width(), size.height());
painter.setWindow(pixmap->rect());
painter.drawPixmap(0,0,*pixmap);/* 数据显示至预览界面 */
}