嵌入式--QT］QPainter 基本绘图
最编程
2024-03-19 19:14:10
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#include "QPainterForm.h"
#include "ui_QPainterForm.h"
#include <QPainter>
QPainterForm::QPainterForm(QWidget* parent)
: QWidget(parent)
, ui(new Ui::QPainterForm)
{
ui->setupUi(this);
//设置窗口背景为白色
setPalette(QPalette(Qt::white));
setAutoFillBackground(true);
}
QPainterForm::~QPainterForm()
{
delete ui;
}
void QPainterForm::paintEvent(QPaintEvent* event)
{
QPainter painter(this);
painter.setRenderHint(QPainter::Antialiasing);
painter.setRenderHint(QPainter::TextAntialiasing);
//宽
int w = this->width();
//高
int h = this->height();
#if 0
//中间区域矩形块
QRect rect(w/4, h/4, w/2, h/2);
//画笔
QPen pen;
pen.setWidth(3);//线宽
pen.setColor(Qt::red);//线条红色
pen.setStyle(Qt::DashLine);//线的样式，实线、虚线
pen.setCapStyle(Qt::FlatCap);//线的断点样式
pen.setJoinStyle(Qt::BevelJoin);//线的连接点样式
painter.setPen(pen);
//画刷
QBrush brush;
brush.setColor(Qt::yellow);//画刷颜色
//Qt::BrushStyle
brush.setStyle(Qt::CrossPattern);//画刷填充样式
painter.setBrush(brush);
//绘图
painter.drawRect(rect);
#endif
#if 0
QPainter painter2(this);
/**
QRadialGradient(qreal cx, qreal cy, qreal radius, qreal fx, qreal fy);
cx xy 辐射填充的中心点，radius 是辐射填充区的半径，fx fy是焦点坐标
**/
QRadialGradient radialGrad(w/2, h/2, qMax(w/8, h/8), w/2, h/2);
//0表示起点
radialGrad.setColorAt(0, Qt::green);
//1表示终点
radialGrad.setColorAt(1, Qt::blue);
radialGrad.setSpread(QGradient::ReflectSpread);
painter2.setBrush(radialGrad);
painter2.drawRect(this->rect());
#endif
// drawArcDemo();
// drawChordDemo();
// drawConvexPolygonDemo();
// drawEllipseDemo();
// drawImageDemo();
// drawLineDemo();
// drawLinesDemo();
// drawPathDemo();
// drawPieDemo();
// drawPixmapDemo();
// drawPointDemo();
// drawPointsDemo();
// drawPolygonDemo();
// drawPolylineDemo();
// drawRectDemo();
// drawRoundedRectDemo();
// dratTextDemo();
// eraseRectDemo();
// fillPathDemo();
// fillRectDemo();
// fivePointedStar();
viewPortAndWindow();
}
void QPainterForm::drawArcDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QRect rect(w/4, h/4, w/2, h/2);
int startAngle = 90 * 16;
int spanAngle = 90*16;
QPainter painter(this);
//画弧线
painter.drawArc(rect, startAngle, spanAngle);
}
void QPainterForm::drawChordDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QRect rect(w/4, h/4, w/2, h/2);
int startAngle = 90 * 16;
int spanAngle = 90*16;
QPainter painter(this);
//画一段弦
painter.drawChord(rect, startAngle, spanAngle);
}
void QPainterForm::drawConvexPolygonDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QPoint points[4] = {QPoint(5*w/12, h/4), QPoint(3*w/4, 5*h/12), QPoint(5*w/12, 3*h/4), QPoint(w/4, 5*h/12)};
QPainter painter(this);
//根据给定的点画凸多边形
painter.drawConvexPolygon(points, 4);
}
void QPainterForm::drawEllipseDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QRect rect(w/4, h/4, w/2, h/2);
QPainter painter(this);
//画椭圆
painter.drawEllipse(rect);
}
void QPainterForm::drawImageDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QRect rect(w/4, h/4, w/2, h/2);
QImage image("图片地址");
QPainter painter(this);
//在指定区域内绘制图片
painter.drawImage(rect, image);
}
void QPainterForm::drawLineDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QLine line(w/4, h/4, w/2, h/2);
QPainter painter(this);
//画直线
painter.drawLine(line);
}
void QPainterForm::drawLinesDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QRect rect(w/4, h/4, w/2, h/2);
QVector<QLine> lines;
lines.append(QLine(rect.topLeft(), rect.bottomRight()));
lines.append(QLine(rect.topRight(), rect.bottomLeft()));
lines.append(QLine(rect.topLeft(), rect.bottomLeft()));
lines.append(QLine(rect.topRight(), rect.bottomRight()));
QPainter painter(this);
//画一批直线
painter.drawLines(lines);
}
void QPainterForm::drawPathDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QRect rect(w/4, h/4, w/2, h/2);
QPainterPath path;
path.addEllipse(rect);
path.addRect(rect);
QPainter painter(this);
//绘制由QPainterPath定义的路线
painter.drawPath(path);
}
void QPainterForm::drawPieDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QRect rect(w/4, h/4, w/2, h/2);
int startAngle = 40*16;
int spanAngle = 120*16;
QPainter painter(this);
//绘制扇形
painter.drawPie(rect, startAngle, spanAngle);
}
void QPainterForm::drawPixmapDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QRect rect(w/4, h/4, w/2, h/2);
QPixmap pixmap("图片地址");
QPainter painter(this);
//绘制QPixmap类型的图片
painter.drawPixmap(rect, pixmap);
}
void QPainterForm::drawPointDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QPainter painter(this);
//绘制一个点
painter.drawPoint(QPoint(w/2, h/2));
}
void QPainterForm::drawPointsDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QPoint points[] = {QPoint(5*w/12, h/4), QPoint(3*w/4, 5*h/12), QPoint(2*w/4, 5*h/12)};
QPainter painter(this);
//绘制一批点
painter.drawPoints(points, 3);
}
void QPainterForm::drawPolygonDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QPoint points[] = {QPoint(5*w/12, h/4), QPoint(3*w/4, 5*h/12), QPoint(5*w/12, 3*h/4), QPoint(2*w/4, 5*h/12)};
QPainter painter(this);
//绘制多边形，最后一个点和第一个点闭合
painter.drawPolygon(points, 4);
}
void QPainterForm::drawPolylineDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QPoint points[] = {QPoint(5*w/12, h/4), QPoint(3*w/4, 5*h/12), QPoint(5*w/12, 3*h/4), QPoint(2*w/4, 5*h/12)};
QPainter painter(this);
//绘制多点连接的线，最后一个点不会和第一个点连接
painter.drawPolyline(points, 4);
}
void QPainterForm::drawRectDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QRect rect(w/4, h/4, w/2, h/2);
QPainter painter(this);
//绘制矩形
painter.drawRect(rect);
}
void QPainterForm::drawRoundedRectDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QRect rect(w/4, h/4, w/2, h/2);
QPainter painter(this);
//绘制圆角矩形
painter.drawRoundedRect(rect, 20, 20);
}
void QPainterForm::dratTextDemo()
{
//宽
int w = this->width();
//高
int h = this->height();
QRect rect(w/4, h/4, w/2, h/2);
QFont font;
font.
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