Qt绘制图形随机验证码（paintEvent）

#include "mytxcode.h" #include <QPainter> #include <QTime> #include <QDebug> MyTXCode::MyTXCode(QWidget *parent) : QWidget(parent) { this->setFixedSize(200, 40); initData(); initVCodeRange(); initVCodeColorList(); changeVCode(); } MyTXCode::~MyTXCode() { } void MyTXCode::setVCodeCount(int vCodeCount) { m_vCodeCount = vCodeCount; } void MyTXCode::setHotPixelCount(int hotPixelCount) { m_hotPixelCount = hotPixelCount; } void MyTXCode::changeVCode() { updateVCode(); updateVCodePic(); } bool MyTXCode::checkVCode(QString vCode) { getNowVCode(); return m_vCode == vCode; } void MyTXCode::paintEvent(QPaintEvent *event) { QPainter painter(this); painter.setRenderHint(QPainter::Antialiasing); painter.fillRect(event->rect(), QBrush(Qt::white)); painter.translate(0, 0); painter.save(); painter.translate(event->rect().center().x() - m_vCodePic.size() / 2 * 14, event->rect().center().y()); for (int i = 0; i < m_vCodePic.size(); i++) { drawConversion(painter); drawVCode(painter, i); painter.translate(20, 0); } painter.restore(); drawOutline(painter); drawHotPixel(painter); } void MyTXCode::initData() { m_vCodeCount = VCODECOUNT; m_hotPixelCount = HOTPIXELCOUNT; m_slopeRange = SLOPERANGE; m_sizeRange = SIZERANGE; m_vCode = ""; m_isChange = false; qsrand(QTime(0,0,0).secsTo(QTime::currentTime())); // 设置随机数种子 // 注:不设置随机种子会导致每次运行程序得到的随机数一样。 } void MyTXCode::initVCodeRange() { m_vCodeRange << "2" << "3" << "4" << "5" << "6" << "7" << "8" << "9" << "a" << "b" << "c" << "d" << "e" << "f" << "g" << "h" << "2" << "3" << "4" << "5" << "6" << "7" << "8" << "9" << "i" << "j" << "k" << "m" << "n" << "o" << "p" << "q" << "2" << "3" << "4" << "5" << "6" << "7" << "8" << "9" << "r" << "s" << "t" << "u" << "v" << "w" << "x" << "y" << "2" << "3" << "4" << "5" << "6" << "7" << "8" << "9" << "z" << "A" << "B" << "C" << "D" << "E" << "F" << "G" << "2" << "3" << "4" << "5" << "6" << "7" << "8" << "9" << "H" << "I" << "J" << "K" << "L" << "M" << "N" << "O" << "2" << "3" << "4" << "5" << "6" << "7" << "8" << "9" << "P" << "Q" << "R" << "S" << "T" << "U" << "V" << "W" << "2" << "3" << "4" << "5" << "6" << "7" << "8" << "9" << "X" << "Y" << "Z" ; } void MyTXCode::initVCodeColorList() { m_vCodeColor << Qt::darkRed << Qt::darkGreen << Qt::darkBlue << Qt::darkCyan << Qt::darkMagenta << Qt::darkYellow << Qt::darkGray; } void MyTXCode::drawVCode(QPainter &painter, int vCodeIndex) { painter.fillPath(*m_vCodePic[vCodeIndex], QBrush(m_vCodeColor[qrand() % m_vCodeColor.size()])); } void MyTXCode::drawOutline(QPainter &painter) { painter.setPen(Qt::darkGreen); painter.setPen(Qt::DashLine); painter.setBrush(Qt::NoBrush); painter.drawRect(0, 0, this->width(), this->height()); } void MyTXCode::drawHotPixel(QPainter &painter) { painter.setPen(Qt::red); painter.setPen(Qt::DotLine); painter.setBrush(Qt::NoBrush); for (int i = 0; i < m_hotPixelCount; i++) painter.drawPoint(QPointF(qrand() % this->width(), qrand() % this->height())); } void MyTXCode::drawConversion(QPainter &painter) { if (qrand() % 2) { // 顺时针旋转 painter.rotate(qrand() % m_slopeRange); } else { // 逆时针旋转 painter.rotate(-(qrand() % m_slopeRange)); } // 随机大小 painter.scale((qrand() % m_sizeRange + (100 - m_sizeRange)) / 100.0 , (qrand() % m_sizeRange + (100 - m_sizeRange)) / 100.0); } void MyTXCode::updateVCode() { m_vCodeList.clear(); for (int i = 0; i < m_vCodeCount; i++) { m_vCodeList << m_vCodeRange[qrand() % m_vCodeRange.size()]; // 产生size以内的随机数[0-(size-1)] } } void MyTXCode::updateVCodePic() { m_vCodePic.clear(); for (int i = 0; i < m_vCodeCount; i++) { // 一个字符一个字符的生成图片 QPainterPath *oneCodePic = new QPainterPath(QPointF(0, 0)); QFont font; font.setBold(true); // 加粗 //font.setPixelSize(20); // 随像素变化字号 font.setPointSize(20); // 肉眼可见固定字号 font.setFamily("Microsoft YaHei"); // 微软雅黑 QRect fontBoundingRect = QFontMetrics(font).boundingRect(m_vCodeList[i]); oneCodePic->addText(-QPointF(fontBoundingRect.center()), font, m_vCodeList[i]); m_vCodePic << oneCodePic; } setVCodePic(m_vCodePic); } void MyTXCode::getNowVCode() { m_vCode = ""; for (int i = 0; i < m_vCodeCount; i++) { m_vCode += m_vCodeList[i]; } } void MyTXCode::setVCodePic(const QList<QPainterPath *> &vCodePic) { m_vCodePic = vCodePic; update(); }