学习 C++ (Part 7: Qt Graphics)

[nonocast]

virtual void paintEvent(QPaintEvent *event);

mainwindow.cpp

void MainWindow::paintEvent(QPaintEvent *event) {
  QPainter textPainter(this);
  textPainter.setFont(QFont("Times", 14, QFont::Bold));
  textPainter.drawText(QPoint(20, 30), "hello world");

  QPainter linePainter(this);
  linePainter.drawLine(QPoint(50, 60), QPoint(100, 100));

  QPainter rectPainter(this);
  rectPainter.setBrush(Qt::BDiagPattern);
  rectPainter.drawRect(QRect(40, 120, 80, 30));

  QPen ellipsePen;
  ellipsePen.setColor(Qt::red);
  ellipsePen.setStyle(Qt::DashDotLine);

  QPainter ellipsePainter(this);
  ellipsePainter.setPen(ellipsePen);
  ellipsePainter.drawEllipse(QPoint(80, 200), 50, 20);

  QPainterPath rectPath;
  rectPath.addRect(QRect(150, 20, 100, 50));

  QPainter pathPainter(this);
  pathPainter.setPen(QPen(Qt::red, 1, Qt::DashDotLine, Qt::FlatCap, Qt::MiterJoin));
  pathPainter.setBrush(Qt::yellow);
  pathPainter.drawPath(rectPath);

  QPainterPath ellipsePath;
  ellipsePath.addEllipse(QPoint(200, 120), 50, 20);

  QPainter ellipsePathPainter(this);
  ellipsePathPainter.setPen(QPen(QColor(79, 106, 25), 5, Qt::SolidLine, Qt::FlatCap, Qt::MiterJoin));
  ellipsePathPainter.setBrush(QColor(122, 163, 39));
  ellipsePathPainter.drawPath(ellipsePath);

  QImage image;
  image.load(":/qt.png");

  QPainter imagePainter(this);
  imagePainter.drawImage(QPoint(150, 200), image);
}

• :/qt.png表示resource中prefix /下的qt.png，如果需要用文件系统，则直接"/foo/bar/qt.png"