Qt创建一个透明图像并修改之

/*创建一个透明图像*/

void crateImage(int w, int h)

{
QSize size(w, h);
QImage image0 = QImage(size, QImage::Format_ARGB32);

QPainter painter(&image0);
painter.setCompositionMode(QPainter::CompositionMode_Source);
painter.fillRect(image0.rect(), Qt::transparent);
painter.setCompositionMode(QPainter::CompositionMode_DestinationIn);

}

/*修改一个透明图像*/

void modifyImage(int w, int h, QPainterPath myPath);

{
QPainter painter(&indicateErrorImage);
painter.setCompositionMode(QPainter::CompositionMode_SourceOver);
QBrush brush(QColor(255, 0, 0, 120), Qt::SolidPattern);
painter.fillPath(myPath, brush);

QPen mypen;
mypen.setColor(QColor(255, 0, 0, 120));
painter.setPen(mypen);
painter.drawPath(myPath);
painter.setCompositionMode(QPainter::CompositionMode_DestinationIn);
painter.end();

}