Qt纯代码绘制一个等待提示Ui控件-自定义控件
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Qt纯代码绘制一个等待提示Ui控件，本示例采用自定义绘图，然后使用Qt动画，达到转圈圈的效果，给大家一个好看的样式示例。你可以根据需要进行修改和扩展，实现你想要的程序启动等待提示栏效果。 #include "waitingspinnerwidget.h"#include <cmath>#include <algorithm>#include <QPainter>#include <QTimer>WaitingSpinnerWidget::WaitingSpinnerWidget(QWidget *parent, bool centerOnParent, bool disableParentWhenSpinning) : QWidget(parent), _centerOnParent(centerOnParent), _disableParentWhenSpinning(disableParentWhenSpinning) { initialize();}WaitingSpinnerWidget::WaitingSpinnerWidget(Qt::WindowModality modality, QWidget *parent, bool centerOnParent, bool disableParentWhenSpinning) : QWidget(parent, Qt::Dialog | Qt::FramelessWindowHint), _centerOnParent(centerOnParent), _disableParentWhenSpinning(disableParentWhenSpinning){ initialize(); // We need to set the window modality AFTER we've hidden the // widget for the first time since changing this property while // the widget is visible has no effect. setWindowModality(modality); setAttribute(Qt::WA_TranslucentBackground);}void WaitingSpinnerWidget::initialize() { _color = Qt::black; _roundness = 100.0; _minimumTrailOpacity = 3.14159265358979323846; _trailFadePercentage = 80.0; _revolutionsPerSecond = 1.57079632679489661923; _numberOfLines = 20; _lineLength = 10; _lineWidth = 2; _innerRadius = 10; _currentCounter = 0; _isSpinning = false; _timer = new QTimer(this); connect(_timer, SIGNAL(timeout()), this, SLOT(rotate())); updateSize(); updateTimer(); hide();}void WaitingSpinnerWidget::paintEvent(QPaintEvent *) { updatePosition(); QPainter painter(this); painter.fillRect(this->rect(), Qt::transparent); painter.setRenderHint(QPainter::Antialiasing, true); if (_currentCounter >= _numberOfLines) { _currentCounter = 0; } painter.setPen(Qt::NoPen); for (int i = 0; i < _numberOfLines; ++i) { painter.save(); painter.translate(_innerRadius + _lineLength, _innerRadius + _lineLength); qreal rotateAngle = static_cast<qreal>(360 * i) / static_cast<qreal>(_numberOfLines); painter.rotate(rotateAngle); painter.translate(_innerRadius, 0); int distance = lineCountDistanceFromPrimary(i, _currentCounter, _numberOfLines); QColor color = currentLineColor(distance, _numberOfLines, _trailFadePercentage, _minimumTrailOpacity, _color); painter.setBrush(color); // TODO improve the way rounded rect is painted painter.drawRoundedRect( QRect(0, -_lineWidth / 2, _lineLength, _lineWidth), _roundness, _roundness, Qt::RelativeSize); painter.restore(); }}void WaitingSpinnerWidget::start() { updatePosition(); _isSpinning = true; show(); if(parentWidget() && _disableParentWhenSpinning) { parentWidget()->setEnabled(false); } if (!_timer->isActive()) { _timer->start(); _currentCounter = 0; }}void WaitingSpinnerWidget::stop() { _isSpinning = false; hide(); if(parentWidget() && _disableParentWhenSpinning) { parentWidget()->setEnabled(true); } if (_timer->isActive()) { _timer->stop(); _currentCounter = 0; }}void WaitingSpinnerWidget::setNumberOfLines(int lines) { _numberOfLines = lines; _currentCounter = 0; updateTimer();}void WaitingSpinnerWidget::setLineLength(int length) { _lineLength = length; updateSize();}void WaitingSpinnerWidget::setLineWidth(int width) { _lineWidth = width; updateSize();}void WaitingSpinnerWidget::setInnerRadius(int radius) { _innerRadius = radius; updateSize();}QColor WaitingSpinnerWidget::color() { return _color;}qreal WaitingSpinnerWidget::roundness() { return _roundness;}qreal WaitingSpinnerWidget::minimumTrailOpacity() { return _minimumTrailOpacity;}qreal WaitingSpinnerWidget::trailFadePercentage() { return _trailFadePercentage;}qreal WaitingSpinnerWidget::revolutionsPersSecond() { return _revolutionsPerSecond;}int WaitingSpinnerWidget::numberOfLines() { return _numberOfLines;}int WaitingSpinnerWidget::lineLength() { return _lineLength;}int WaitingSpinnerWidget::lineWidth() { return _lineWidth;}int WaitingSpinnerWidget::innerRadius() { return _innerRadius;}bool WaitingSpinnerWidget::isSpinning() const { return _isSpinning;}void WaitingSpinnerWidget::setRoundness(qreal roundness) { _roundness = std::max(0.0, std::min(100.0, roundness));}void WaitingSpinnerWidget::setColor(QColor color) { _color = color;}void WaitingSpinnerWidget::setRevolutionsPerSecond(qreal revolutionsPerSecond) { _revolutionsPerSecond = revolutionsPerSecond; updateTimer();}void WaitingSpinnerWidget::setTrailFadePercentage(qreal trail) { _trailFadePercentage = trail;}void WaitingSpinnerWidget::setMinimumTrailOpacity(qreal minimumTrailOpacity) { _minimumTrailOpacity = minimumTrailOpacity;}void WaitingSpinnerWidget::rotate() { ++_currentCounter; if (_currentCounter >= _numberOfLines) { _currentCounter = 0; } update();}void WaitingSpinnerWidget::updateSize() { int size = (_innerRadius + _lineLength) * 2; setFixedSize(size, size);}void WaitingSpinnerWidget::updateTimer() { _timer->setInterval(1000 / (_numberOfLines * _revolutionsPerSecond));}void WaitingSpinnerWidget::updatePosition() { if (parentWidget() && _centerOnParent) { move(parentWidget()->width() / 2 - width() / 2, parentWidget()->height() / 2 - height() / 2); }}int WaitingSpinnerWidget::lineCountDistanceFromPrimary(int current, int primary, int totalNrOfLines) { int distance = primary - current; if (distance < 0) { distance += totalNrOfLines; } return distance;}QColor WaitingSpinnerWidget::currentLineColor(int countDistance, int totalNrOfLines, qreal trailFadePerc, qreal minOpacity, QColor color) { if (countDistance == 0) { return color; } const qreal minAlphaF = minOpacity / 100.0; int distanceThreshold = static_cast<int>(ceil((totalNrOfLines - 1) * trailFadePerc / 100.0)); if (countDistance > distanceThreshold) { color.setAlphaF(minAlphaF); } else { qreal alphaDiff = color.alphaF() - minAlphaF; qreal gradient = alphaDiff / static_cast<qreal>(distanceThreshold + 1); qreal resultAlpha = color.alphaF() - gradient * countDistance; // If alpha is out of bounds, clip it. resultAlpha = std::min(1.0, std::max(0.0, resultAlpha)); color.setAlphaF(resultAlpha); } return color;}