如何清除qcustomplot 中的vLine
时间: 2024-05-04 09:20:19 浏览: 9
要清除 QCustomPlot 中的 vLine,可以使用 QCPItemLine::setVisible() 函数将其设置为不可见,然后使用 QCustomPlot::replot() 函数重新绘制 QCustomPlot。例如:
```cpp
// 获取 QCustomPlot 中的第一个 QCPItemLine
QCPItemLine *vLine = qcustomplot->itemAt(0);
// 将 QCPItemLine 设置为不可见
vLine->setVisible(false);
// 重新绘制 QCustomPlot
qcustomplot->replot();
```
请注意,这只是将 QCustomPlot 中的第一个 QCPItemLine 设置为不可见。如果您有多个 QCPItemLine,您需要相应地修改代码以处理它们。
相关问题
matlab vline
The `vline` function in MATLAB is used to draw vertical lines on a plot.
Syntax:
```matlab
vline(x)
vline(x,'LineStyle')
vline(x,'LineStyle','Color')
```
- `x` is a scalar or a vector of x-coordinates where the vertical line(s) should be drawn.
- `'LineStyle'` is an optional parameter that specifies the style of the line(s) to be drawn. The default value is `'-'`.
- `'Color'` is an optional parameter that specifies the color of the line(s) to be drawn. The default value is `'k'` (black).
Example:
```matlab
x = 0:0.1:pi;
y = sin(x);
plot(x, y)
vline(pi/2, '--r')
```
This code will plot the sine function from 0 to pi and draw a vertical dashed red line at x=pi/2.
QT 中QStripLinesCollection使用
QStripLinesCollection是Qt中的一个类,用于绘制图表中的垂直或水平线条。可以通过以下步骤在Qt中使用QStripLinesCollection:
1. 创建QCustomPlot对象:
```cpp
QCustomPlot *customPlot = new QCustomPlot(this);
```
2. 添加一条垂直线:
```cpp
QCPItemStraightLine *vLine = new QCPItemStraightLine(customPlot);
vLine->setPen(QPen(Qt::red));
vLine->point1->setCoords(2, 0);
vLine->point2->setCoords(2, 10);
```
3. 添加一条水平线:
```cpp
QCPItemStraightLine *hLine = new QCPItemStraightLine(customPlot);
hLine->setPen(QPen(Qt::green));
hLine->point1->setCoords(0, 5);
hLine->point2->setCoords(10, 5);
```
4. 添加QStripLinesCollection对象:
```cpp
QCPItemStraightLine *stripLine1 = new QCPItemStraightLine(customPlot);
stripLine1->setPen(QPen(Qt::blue));
stripLine1->point1->setCoords(4, 0);
stripLine1->point2->setCoords(4, 10);
QCPItemStraightLine *stripLine2 = new QCPItemStraightLine(customPlot);
stripLine2->setPen(QPen(Qt::blue));
stripLine2->point1->setCoords(6, 0);
stripLine2->point2->setCoords(6, 10);
QStripLinesCollection *stripLines = new QStripLinesCollection(customPlot);
stripLines->add(stripLine1);
stripLines->add(stripLine2);
```
5. 显示图表:
```cpp
customPlot->replot();
```
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