Question

将QCPItemLine与图层一起使用的正确方法是什么？我有一个pixamp，我用QCustomPlot绘制在网格上，我想在像素图上方绘制一条线，到目前为止，它已显示在像素图下方。

让我说我已经设置了一个像素图，如何确定行将显示在哪里？根据文献记载，画线的方法是：

QCOItemLine* line = new QCOItemLine(ui->grid);

_line->start->setCoords(x_tail, y_tail);
_line->end->setCoords(x_head, y_head);

ui->widget->replot();

与指向与特定图形或图层相关的线剂量不同，该如何管理？

这是我设置像素图的方式：

QCPItemPixamp* _pixmap;
Qimage image;
getImageData(image);

ui->grid->addLayer("map", ui->grid->layer("main));

QPixmap pixels = QPixmap::fromImage(image.scaled(ui->grid->width(), 
ui->grid->height(), Qt::IgnoreAspectRatio, Qt::FastTransformation));

_pixmap->setVisible(true);
_pixmap->setScaled(true);
_pixmap->setPixmap(pixels);

_pixmap->topLeft->setCoords(left_x, bottom_y);
_pixmap->bottomRight->setCoords(right_x, top_y);

我想在此像素图上方画一条线

Answer 1

您必须为每个项目设置不同的图层，然后可以使用// create layers ui->grid->addLayer("line"); ui->grid->addLayer("pixmap"); //create line QCPItemLine* _line = new QCPItemLine(ui->grid); _line->start->setCoords(1, 5); _line->end->setCoords(5, 3); //set layer _line->setLayer("line"); //create pixmap QCPItemPixmap *_pixmap = new QCPItemPixmap(ui->grid); QImage image; getImageData(image); QPixmap pixels = QPixmap::fromImage(image.scaled(ui->grid->width(), ui->grid->height(), Qt::IgnoreAspectRatio, Qt::FastTransformation)); _pixmap->setPixmap(pixels); _pixmap->setVisible(true); _pixmap->setScaled(true); _pixmap->topLeft->setCoords(1, 5); _pixmap->bottomRight->setCoords(5, 3); // set layer _pixmap->setLayer("pixmap"); // move layers ui->grid->moveLayer(_line->layer(), _pixmap->layer(), QCustomPlot::limAbove ); ui->grid->replot();移动这些图层。

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QCPItemLine使用图层

1 个答案: