qt模拟CSS3之box-shadow效果

#include "mainwindow.h" #include "ui_mainwindow.h" #include <QPushButton> #include <QMessageBox> #include <QGraphicsDropShadowEffect> #include <QDebug> #include <QPainter> MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) { ui->setupUi(this); ui->pushButton->setFocusPolicy(Qt::NoFocus); connect(ui->pushButton, SIGNAL(pressed()), this, SLOT(paintBorder())); connect(ui->pushButton, SIGNAL(released()), this, SLOT(paintBorder())); } MainWindow::~MainWindow() { delete ui; } /* * 前提条件 * border图绝对的中心对称与轴对称 * ----------- * 重要参数 * ----------- * border_width: 边缘宽度 * border_radius: 边缘转角半径 * */ void MainWindow::paintEvent(QPaintEvent *event) { QPainter painter(this); QPixmap background = QPixmap(":/image/radius_border.png"); int background_width = background.width(); // 背景图片宽度 int background_height = background.height(); // 背景图片高度 int border_width = 5; int border_radius = 5; int original_border = 1; int corner_width = border_width + border_radius; int corner_height = border_width + border_radius; /* 以顺时针方向旋转的边界 */ QPixmap leftTop = background.copy(0, 0, corner_width, corner_height); QPixmap top = background.copy(corner_width, 0, background_width - 2 * corner_width, border_width); QPixmap rightTop = background.copy(background_width - corner_width, 0, corner_width, corner_height); QPixmap right = background.copy(background_width - border_width, corner_height, border_width, background_height - 2 * corner_height); QPixmap rightBottom = background.copy(background_width - corner_width, background_height - corner_height, corner_width, corner_height); QPixmap bottom = background.copy(corner_width, background_height - border_width, background_width - 2 * corner_width, border_width); QPixmap leftBottom = background.copy(0, background_height - corner_height, corner_width, corner_height); QPixmap left = background.copy(0, corner_height, border_width, background_height - 2 * corner_height); if(ui->pushButton->isDown()) { QRect rect = ui->lineEdit->geometry(); int startX = rect.left(); int endX = rect.right(); int startY = rect.top(); int endY = rect.bottom(); int width = rect.width(); int height = rect.height(); painter.drawPixmap(startX - border_width, startY - border_width, leftTop); painter.drawPixmap(startX + border_radius, startY - border_width, width - 2 * border_radius - original_border, border_width, top); painter.drawPixmap(endX - border_radius, startY - border_width, rightTop); painter.drawPixmap(endX, startY + border_radius, border_width, height - 2 * border_radius - original_border, right); painter.drawPixmap(endX - border_radius, endY - border_radius, rightBottom); painter.drawPixmap(startX + border_radius, endY , width - 2 * border_radius - original_border, border_width, bottom); painter.drawPixmap(startX - border_width, endY - border_width, leftBottom); painter.drawPixmap(startX - border_width, startY + border_radius, border_width, height - 2 * border_radius - original_border, left); } if(ui->lineEdit->hasFocus()) { } if(ui->lineEdit_2->hasFocus()) { } } void MainWindow::paintBorder() { this->update(); }