你如何在QT中绘制点？ [英] How do you plot points in QT?

问题描述

我在C ++中使用QT编写一个应用程序，其中有n个点并计算凸包。但是，一旦计算，我不知道如何绘制点和绘制船体的边框。制作菜单按钮等非常简单，但我不确定我是否知道这样做的工具。

I am writing an application in C++ with QT where you have n points and compute the convex hull of this. However, once this is computed I have no idea how to plot the points and draw the border of the hull. Making menu buttons and such is simple enough, but I'm not sure I know the tools to do this.

如何做？

推荐答案

您可以创建一个自定义类派生自 QWidget ，其中您覆盖 void paintEvent（QPaintEvent * event）方法。因为你把点放到某种点列表中， std :: vector< QPoint> 或 QList< QPoint> 然后使用Polyline方法绘制它。例如：

You can just create a custom class deriving from QWidget where you override the void paintEvent(QPaintEvent* event) method. In that you put the points into some sort of point list, either std::vector<QPoint> or QList<QPoint> and then paint it with a Polyline method. For instance:

void Foo::paintEvent(QPaintEvent* event)
{
  QPainter painter(this);
  std::vector<QPoint> points;
  // Fill points with the points
  painter.drawPolyLine(points.data(), static_cast<int>(points.size()));
}

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