Qt QPixmap QPainter问题
我有一段代码,其中包含以下代码行:Qt QPixmap QPainter问题,qt,qpainter,qpixmap,Qt,Qpainter,Qpixmap,我有一段代码,其中包含以下代码行: int dsize = 100; QPainter *painter; QPixmap *img; QLabel *l_img; painter = new QPainter; img = new QPixmap(dsize, dsize); l_img = new QLabel; l_img->setPixmap(*img); painter->begin(img); painter->fillRect(img->rect(),
int dsize = 100;
QPainter *painter;
QPixmap *img;
QLabel *l_img;
painter = new QPainter;
img = new QPixmap(dsize, dsize);
l_img = new QLabel;
l_img->setPixmap(*img);
painter->begin(img);
painter->fillRect(img->rect(), Qt::white);
QPen pen(Qt::black, 12);
painter->setPen(pen);
painter->drawLine(40, 40, 40, 100);
painter->end();
l_img->show();
然而,当我运行代码时,我没有看到任何带有黑色矩形的白色图像。事实上,我看到的是用大字体写的窗口标题。似乎什么都不管用,我只是得到了这样的图像。我做错了什么
谢谢大家! 明白了
它有这样一行:
l_img->setPixmap(*img);
应该是在
painter->end();
谢谢你,xD。img=new QPixmapdsize,dsize;