Qt 生成一张图片

QImage saveImage(QSize(imageWidth,imageHeigth),QImage::Format_RGB888);
QFile file(filePath);
if (!file.open(QIODevice::ReadWrite))
    {
	return false;
    }
QByteArray ba;
QBuffer buffer(&ba);
buffer.open(QIODevice::WriteOnly);
saveImage.fill(QColor(Qt::black).rgb());
saveImage.save(&buffer,"JPG");
file.write(ba);

原文：http://blog.csdn.net/sunny_unix/article/details/45875413